5-Methyl-furfuryl furfuryl ether

ABSTRACT

The compound 5-methyl-furfuryl furfuryl ether which is useful as a flavor additive for foodstuffs and beverages.

This is a division of application Ser. No. 482,691 filed June 24, 1974which is a division of application Ser. No. 243,866 filed Apr. 13, 1972and now abandoned which is a division of application Ser. No. 70,560filed Sept. 8, 1970 now U.S. Pat. No. 3,702,253; which latterapplication is a continuation of now-abandoned application Ser. No.543,069 filed Apr. 18, 1966, which is a continuation-in-part ofnow-abandoned application Ser. No. 452,342 filed Apr. 30, 1965.

The invention relates to flavor agents in general. More particularly theinvention relates to chemical compounds or compositions which have beenfound to have utility in the alteration of flavor or flavorcharacteristics of substances, whether naturally occurring or synthetic.Still more particularly the invention relates to a group of chemicalcompounds which have been found to be useful in the area of flavor-notealteration, whether by the enhancement of flavors or flavor-notes thatare characteristic in a substance, by the alteration of a flavor or aflavor-note from a less to a more desirable one, or by the complete orpartial masking of a flavor or flavor-note.

As is generally recognized by those familiar with the art, the scienceof flavor technology is an extremely complex one. Although much is knownabout flavor and flavor technology there is still a great deal to belearned in the field and the body of scientific literature is beingrapidly expanded by those working in the area. The technology of flavorsynthesis and blending of various flavor elements to achieve certaindesirable results is of great commercial importance at the present stageof industrial advance. Commercial production of consumer goods fromsynthetic starting materials is becoming more and more common, anddesirable, as world population continues to increase its demands uponthe finite capacity for the production of natural products. Industry isalso continually seeking means of upgrading natural products -- methodsof altering or enhancing the qualities of taste of less desirablenatural products -- usually more abundant -- into more desirable productqualities. Often, for example, a product can be made commerciallyattractive only by masking or blanking out an undesirable flavorcomponent. Formerly, before the advent of the flavor chemist and histechnology, this unit of production would have been lost, or at least,would have had to have been re-processed to a useable quality. By theuse of specifically designed flavoring agents, however, the undesirableflavor note can be eliminated or masked with another desirable one, andthe expensive and time-consuming re-processing step eliminated or theproduction batch saved for use. Too, it is common in some segments ofthe industry, particularly the food industry, to add flavor agents toproduction units to enhance or bring out a desirable flavorcharacteristics of products -- and by so doing to render the productmore desirable from a consumer preference standpoint.

It is the object of this invention theefore, to provide the flavortechnologist with additional tools for his use in the alteration of foodflavors, whether it be flavor or flavor-note alteration generally or theenhancement or improvement of flavor or flavor notes specifically.

It is a further object of the invention to furnish a group of chemicalcompositions which have utility in the technology of flavor alteration,whether added to solid or liquid compositions for human consumption, andwhich may be used in either solid or liquid form.

A further object of the invention is to describe several groups ofchemical compounds having desirable utility as flavor agents which maybe prepared synthetically, thus enabling the food technologist to alteror enhance his product without drawing upon a natural product for theflavor agent.

A still further object of the invention is to describe a group ofchemical compounds capable of synthesis from readily available organicsubstances which may be used singly or in combination to alter theflavor or flavor notes of compositions for food use, whether used inmicro-quantities such as parts-per-million or in larger quantities, asthe dictates of the end results may require.

Other objects will become apparent to those skilled in the art as thedescription proceeds.

Thus, in accordance with the concept of the instant invention, there isset out below a series of groups of compounds which have been found tohave utility as flavor agents and to represent valuable materials to thefood technologist who wishes to alter the flavor components of foods orfood products either liquid foods or beverages, such as fruit andvegetable juices, milk, coffee, tea, cocoa, chocolate, and the like orsolid foods such as cereals, flours, confections, vegetables, meats,etc. The flavor agents may be used either in liquid or solid form andare used in quantities designed to give the desired results, as will bemore clearly explained as the description proceeds.

The chemical compounds which have been found to have utility as flavoragents may be generally classified according to the following groups:I.DiphenylsII. Substituted NaphthalenesIII. Furan HydrocarbonsIV.Thiophene HydrocarbonsV. Pyrrole HydrocarbonsVI. PyridineHydrocarbonsVII. Pyrazine HydrocarbonsVIII. Aliphatic and AromaticAlcoholsIX. Furan EthersX. Thiophene EthersXI. Thiazole AlcoholsXII.Pyridine Ethers and AlcoholsXIII. Pyrazine Ethers and AlcoholsXIV.Benzofuran Carbonyl CompoundsXV. Thiophene AldehydesXVI. PyrroleAldehydesXVII. Pyrazine Carbonyl CompoundsXVIII. Aliphatic and AromaticKetonesXIX. Furan KetonesXX. Thiophene KetonesXXI. Pyrrole KetonesXXII.Thiazole Carbonyl CompoundsXXIII. Pyridine Carbonyl CompoundsXXIV.α-DiketonesXXV. Thiophene-α-diketonesXXVI. Pyrrol-α-diketonesXXVII.Furan EstersXXVIII. Thiophene EstersXXIX. Pyridine EstersXXX. AromaticSulfur CompoundsXXXI. Furan Sulfur CompoundsXXXII. Thiophene SulfurCompoundsXXXIII. Pyridine Sulfur CompoundsXXXIV. Pyrrole SulfurCompoundsXXXV. Pyrazine Sulfur CompoundsXXXVI. Phenols and PhenolEthersXXXVII. Aliphatic OxoalcoholsXXXVIII. Miscellaneous

The above groupings are selected more for reasons of chemical similaritythan because of flavor alteration characteristics as will be morespecifically described in relation to the more complete definitionafforded each particular group.

The flavor agents or flavor modifying compositions of this invention areavailable to the food technologists in a variety of forms. It is usuallypreferable to use the agents in the form of a solution, for ease ofdilution, exactitude of measurement, efficiency of distribution in theend use, etc. However the chemical nature of the compound, itssolubility in acceptable solvents, its stability, and othercharacteristics may dictate the form in which it is used.

The amounts of the agents used is also subject to wide variation, ofcourse. More concentrated materials, and those with the greatest degreeof flavor modifying ability will be used in lesser amounts. Some degreeof experimentation is, of course, required to achieve the desiredresults. A small, but flavor modifying amount, of the agents is blendedwith the material whose total flavor is to be altered, the amountdepending upon the end result desired.

Two different types of methods were used in testing the compounds listedin this specification for their utility as flavor agents, flavormodifiers, flavor alteration agents, flavor-note enhancers, and thelike. The first type method (A) served the purpose of determining theintrinsic taste, flavor and aroma of each individual compound. Thesecond type methods (B) and (C) were used for testing theflavor-and-aromo-modifying or-enhancing effects of the compoundshereinafter listed on coffee products and more particularly onspray-dried soluble coffee products commercially known as "instantcoffee".

Method A

The vehicle used for testing the flavor compounds was a 65% solution ofcane sugar in tap water. The flavor compounds were incorporated in thissugar syrup in the form of 1% or 1 per 1000 by weight solutions in 96%ethyl alcohol. The concentration of the flavor compounds in the sugarsyrup varied between about 0.005 and 5 g. for 100 liters of syrupaccording to the varying strength of flavor compounds. Samples of eachflavored sugar syrup were submitted to the members of the tastingpanels. After testing the samples each member had to give an evaluationof each flavor compound in terms of descriptive words.

In the evaluation of materials for the alteration or enhancement ofcoffee flavor or of coffee flavor notes it is essential that theequipment used, coffee pots, cups, spoons, measuring equipment, etc. beabsolutely clean prior to use.

Method B

The coffee base was prepared by dissolving 1 g. of a commercialspray-dried soluble coffee in boiling water. A sufficient number of potswas prepared to provide one pot for each flavor agent to be evaluatedplus one control. The flavor agent was added to the coffee base in theform of a 1% or 1 per 1000 by weight alcoholic solution atconcentrations varying between 0.005 and 5 g. of flavor agent for 100liters of coffee base. The measured quantity of the flavor agent wasadded to a pot of the coffee base material, stirred well, and pouredimmediately into cups for the organoleptic evaluation. The taste testsweremade within a short time (not more than 15 minutes) after the finalcomposition to be tested was prepared.

The organoleptic evaluation involved grading a series of cups that werecoded, the taster merely rating the coded cups against the standard orcontrol which did not contain the flavor agent. The standard was placedat the first position in a series of cups. The tasters were asked toascertain whether or not there existed differences in the flavor of thesamples to be tested as compared with the control. The tasters werefurthermore asked to describe and characterize the various flavor notesand types determined.

Method C

Using boiling Crystal Spring Water, to provide a clean starting taste, a1.35% solution of relatively bland tasting commercially availablespray-dried soluble coffee was prepared. The containers used --preferably the lower portion of a glass coffee maker -- was absolutelyclean, as was the other equipment used, e.g. cups and spoons.

A sufficient number of containers, or pots, were used to accommodateeach flavor fraction to be sutdied, plus one control. The flavorfraction was measured carefully with a micro-syringe, adding from 2 to150 microliters of the flavor fraction per pot. The mixture of coffeesolution and flavor fraction was stirred and immediately poured intocups for tasting. At least 5 experienced tasters are used. The tastingshould begin at least within 15 minutes after the solution is prepared.If not, the solution should be discarded and fresh solution prepared.

The cups are coded and the samples are not indentified. A standardsample is included in which no flavor fraction has been added. Thetaster is asked to identify and describe the flavor enhancement ormodification noted.

In the following specific description of the compounds of the Groupslisted above (I - XXXVIII) there is first given the structural formulafollowed by a list of members of the group which have been found to haveoutstanding utility in the concept of this invention. Immediatelyfollowing the chemical name of each member there is given the commercialsource or a literature reference giving a method for its preparation.Commercially available products will be identified by the abbreviationo.a., and may be obtained from FLUKA, A. G., Buchs S. G., Switzerland;ALDRICH CHEM. CO., Milwaukee, Wis.; DR. F. RASCHIG GMBR, Ludwigzhafen a.Rh., West-Germany; or K & K LABORATORIES INC., Plainview, N.Y. 11803.

In those instances wherein new compounds are described a detailed methodof preparation is given following the list of the group members. Newcompounds will be identified by the abbreviation n.c.

The results of the organoleptic evaluation taste are set out in thegroup of TABLES following the detailed description of the group ofcompounds.

I. -- Diphenyls

In this first group of compounds are included those having thestructural formula: ##SPC1##

wherein R is hydrogen or an alkyl group, e.g. methyl,

Typical compounds are:

    (1) a. diphenyl              c.a.                                             b.     2-methyl-diphenyl     c.a.                                             c.     3-methyl-diphenyl     c.a.                                             d.     4-methyl-diphenyl     c.a.                                             e.     4,4'-dimethyl-diphenyl                                                                              c.a.                                         

Organoleptic evaluations as flavor agents are described in TABLE Ibelow.

II. -- Substituted Naphthalenes

Compounds in this group are those having the general formula: ##SPC2##

wherein R is hydrogen or an alkyl group, e.g. methyl or ethyl, at leastone of the R's being an alkyl group.

Typical compounds include:

    (1) a. alpha-methyl-naphthalene                                                                              c.a.                                           b.     beta-methyl-naphthalene c.a.                                           c.     beta-ethyl-naphthalene  c.a.                                           d.     1,2-dimethyl-naphthalene                                                                              c.a.                                           e.     1,3-dimethyl-naphthalene                                                                              c.a.                                           f.     1,4-dimethyl-naphthalene                                                                              c.a.                                           g.     1,5-dimethyl-naphthalene                                                                              c.a.                                           h.     1,6-dimethyl-naphthalene                                                                              c.a.                                           i.     2,3-dimethyl-naphthalene                                                                              c.a.                                           j.     2,6-dimethyl-naphthalene                                                                              c.a.                                           k.     1,3,7-trimethyl-naphthalene                                                                           c.a.                                           l.     2,3,5-trimethyl-naphthalene                                                                           c.a.                                           m.     2,3,6-trimethyl-naphthalene                                                                           c.a.                                           n.     alpha-ethyl-naphthalene c.a.                                           o.     1,7-dimethyl-naphthalene                                                                              c.a.                                           p.     2,7-dimethyl-naphthalene                                                                              c.a.                                       

The compounds enumerated above were evaluated organoleptically and gavethe results set out in TABLE II below.

III. -- Furan Hydrocarbons

The compounds of this group which have utility according to theinventive concept are selected from the class of compounds having thegeneral formula: ##SPC3##

wherein R is hydrogen or an alkyl group containing from 1 to 3 carbonatoms;

compounds of the formula: ##SPC4##

wherein R is hydrogen or an alkyl or an alkenyl group of from 1 to 3carbon atoms, provided that the sum of the carbon atoms of thesubstituent groups does not exceed 3; and compounds of the forumla:##SPC5##

wherein R₁ is hydrogen or a methyl group and wherein R₂ is ##SPC6##

or ##SPC7##

R₃ being hydrogen or a methyl group such that R₁ and R₃ are not bothhydrogen.

Specific compounds included in this group of compounds are:

    (1) a.                                                                            2-vinyl-furan      Bull. 1947. 453                                        b.  2-(1)-pentenyl-furan                                                                             C.A. 1961. 85905f                                      (2) a.                                                                            benzofuran         c.a.                                                   b.  2-methyl-benzofuran                                                                              Sec. 1955. 3689                                        c.  2-ethyl-benzofuran J.A.C.S. 73. 754 (1951)                                d.  2,3-dimethyl-benzofuran                                                                          Sec. 1955. 3689                                        e.  2-vinyl-benzofuran J.A.C.S. 73. 754 (1951)                                f.  2-isopropenyl-benzofuran                                                                         n.c.                                                   g.  7-methyl-benzofuran                                                                              J.Chem.Soc. 1920 1534                                  h.  7-ethyl-benzofuran n.c.                                                   i.  2,7-dimethylbenzofuran                                                                           n.c.                                                   (3) a.                                                                            2,2'-difuryl       J.A.C.S. 73. 1271 (1951)                               b.  5-methyl-2,2'-difuryl-methane                                                                    C.A. 1957. 6594a                                       c.  5,5'-dimethyl-2,2'-difuryl-methane                                                               Helv. 1932. 1068                                   

The new compounds included in Group III can be prepared by the methodsdescribed below.

2. f. 2-Isopropenyl-benzofuran. According to the method described inJ.A.C.S. 75, 754 (1951) 2-acetyl-benzofuran is reacted withmethyl-magnesium bromide to form 2-(2-hydroxyisopropyl)-benzofuran whichis converted to its acetate. Pyrolysis of the acetate yields2-isopropenyl-benzofuran of b.p. 81°-83°C./0.001 mm. Hg.

2. h. 7-Ethyl-benzofuran is prepared by the method described in J. Chem.Soc. 1920, 1534, but using o-ethylphenol of o-cresol. The MS. of theproduct thus obtained shows the following ion peaks with the relativeintensities given within brackets: 131 (100%), 146 (38%) and 77 (10%).

2. i. 2,7-Dimethyl-benzofuran. 7-Methyl-benzofuran (of. compound (2) g.)is subjected to a WILSMEYER reaction to form7-methyl-benzofuran-2-aldehyde which is converted into2,7-dimethyl-benzofuran by a WOLFF-KISHNER reaction by the methoddescribed in Bull.Soo.Chim.France 29, 1875 (1952). The product thusobtained has the following peaks in its MS: 146 (100%), 145 (92%) and131 (32%).

Organoleptic evaluations of this group of compounds are set out in TABLEIII below.

IV. -- Thiophene Hydrocarbons

The thiophene hydrocarbons having utility in accordance with the instantinventive concept are those compounds described by the structuralformula: ##SPC8##

wherein R₁ and R₂ are hydrogen, methyl, ethyl, vinyl or propyl, thecompound of the formula: ##SPC9##

the compound of the formula: ##SPC10##

wherein R₁ and R₂ are hydrogen or methyl groups, and wherein X is oxygenor sulfur;

the compounds of the formula ##SPC11##

wherein R₁ and R₂ are hydrogen or methyl groups, and the compounds ofthe formula ##SPC12##

wherein R₁ and R₂ represent hydrogen or alkyl groups.

Typical compounds of this class of compounds are:(1) a.2-methyl-thiophene c.a.b. 3-methyl-thiophene c.a.c. 2-ethyl-thiophenec.a.d. 3-ethyl-thiophene Bull. 1955. 424e. 2-propyl-thiophene J.A.C.S.70. 391. Bull. - 1955. 361f. 2-vinyl-thiophene Bull. 1955. 424g.3-vinyl-thiophene Bull. 1955. 424h. 2-methyl-4-ethyl-thiopheneJ.A.C.S.75.989 (1953)i. 2-methyl-5-ethyl-thiophene J.A.C.S.75.989(1953)j. 2-methyl-5-propyl-thiophene J.A.C.S.75.989 (1953)k.2,5-dimethyl-thiophene c.a.(2) a. 2,3,3',2'-thiophenothiophene Soc.1953.1837(3) a. 2,2'-dithienyl-methane J.A.C.S.73. 1270 (1951)b.5,5'-dimethyl-2,2'-dithienyl-methane J.A.C.S.73. 1270 (1951)c.2-furyl-2-thienyl-methane C.A. 57. 9776f (1962)d.(5-methyl-2-thienyl)-2-furyl-methane C.A. 57. 9776F (1962)(4) a.2,2'-dithienyl J.A.C.S.78. 1958 (1956)b.5,5'-dimethyl-2,2'-dithienyl-methane J.A.C.S.78. 1958 (1956)(5) a.benzothiophene c.a.b. 2-methyl-benzothiophene J.A.C.S.74. 664 (1952)

Organoleptic evaluations of these compounds are set out in TABLE IVbelow.

V. -- Pyrrole Hydrocarbons

Compounds of this group have the general formulae: ##SPC13##

wherein R is alkyl, e.g. ethyl, amyl, isoamyl, or alphamethylbutyl, and##SPC14##

wherein X is oxygen or sulfur and R is hydrogen or a methyl group,provided that, if X represents oxygen, R is methyl.

Typical compounds of this group include:(1) a. 1-ethyl-pyrrole Helv.10,387 (1927) b. 1-n-amyl-pyrrole Helv.10, 387 (1927) c. 1-isoamyl-pyrroleHelv.10, 387 (1927) d. 1-(alphamethyl-butyl)-pyrrole Helv.10, 387(1927)(2) a. 1-(5-methyl-2-furfuryl)-pyrrole n.c.; b.p.104°C./11 mmprepared by the same method as (1) a. b. 1-thienyl-pyrroleJ.Org.Chem.28, 1574 (1963)

Organoleptic test evaluations are set out in TABLE V below.

VI -- Pyridine Hydrocarbons

The compounds of this group which have utility according to the instantconcept are to be described as falling under the general formula:##SPC15##

wherein R₁, R₂ and R₃ are hydrogen, alkyl, e.g. methyl, ethyl, isobutyl;alkenyl groups, e.g. vinyl, propenyl; aryl groups; or aralkyl groups;provided that the symbols R₁, R₂ and R₃ are not all hydrogen.

Typical compounds include:

    (1)  a.    2-methyl-pyridine  c.a.                                                 b.    3-methyl-pyridine  c.a.                                                 c.    3-ethyl-pyridine   c.a.                                                 d.    2-allyl-pyridine   Bull. 420, (1955)                                    e.    4-isobutyl-pyridine                                                                              Bull. 420, (1955)                                    f.    2-(1)-propenyl-pyridine                                                                          Ann. 247, 1 (1888)                              (1)  g.    4-(1)-propenyl-pyridine                                                                          Ann. 247, 1 (1888)                                   h.    2-methyl-5-ethyl-pyridine                                                                        c.a.                                                 i.    2,3-dimethyl-pyridine                                                                            c.a.                                                 j.    2,4-dimethyl-pyridine                                                                            c.a.                                                 k.    2,5-dimethyl-pyridine                                                                            c.a.                                                 l.    2,6-dimethyl-pyridine                                                                            c.a.                                                 m.    3,4-dimethyl-pyridine                                                                            c.a.                                                 n.    3,5-dimethyl-pyridine                                                                            c.a.                                                 o.    2-vinyl-pyridine   c.a.                                                 p.    4-methyl-pyridine  c.a.                                                 q.    2-methyl-6-vinyl-pyridine                                                                        c.a.                                                 r.    4-phenyl-pyridine  c.a.                                                 s.    4-benzyl-pyridine  c.a.                                                 t.    2-benzyl-pyridine  c.a.                                                 u.    2-methyl-5-ethyl-pyridine                                                                        c.a.                                            Organoleptic evaluations are set out in TABLE                                 VI below.                                                                 

VII -- Pyrazine Hydrocarbons

This important group of compounds have been found to have exceptionalutility as flavor agents in accordance with the instant inventiveconcept. Compounds of the group have the general formulae: ##SPC16##

wherein R₁ is hydrogen, alkyl, 1-pyrrolyl or 2-thienyl; and R₂ is alkylor alkenyl, ##SPC17##

wherein R₁, R₂ and R₃ are alkyl groups having from 1 to 5 carbon atoms,##SPC18##

wherein R₁, R₂ and R₃ are hydrogen or methyl groups, ##SPC19##

wherein R₁ and R₂ are alkyl groups containing from 1 to 3 carbon atoms,##SPC20##

wherein R₁, R₂, R₃ and R₄ are alkyl groups containing from 1 to 6 carbonatoms, and ##SPC21##

wherein R₁ is methyl or ethyl and R₂ is alkyl or alkenyl with C₁ to C₆.

Compounds of this group which are of special interest include:

    (1)                                                                              a.                                                                              2-methyl-3-ethyl-pyrazine                                                                          n.c.                                                   b.                                                                              2-methyl-3-isobutyl-pyrazine                                                                       n.c.                                                   c.                                                                              2-methyl-3-propyl-pyrazine                                                                         n.c.                                                   d.                                                                              2-methyl-3-isopropyl-pyrazine                                                                      n.c.                                                   e.                                                                              2-methyl-3-butyl-pyrazine                                                                          n.c.                                                   f.                                                                              2-methyl-3-amyl-pyrazine                                                                           n.c.                                                (1)                                                                              g.                                                                              2-methyl-3-hexyl-pyrazine                                                                          n.c.                                                   h.                                                                              2,3-dimethyl-pyrazine                                                                              Ber. 40, 4855 (1907)                                   i.                                                                              2,3-diethyl-pyrazine n.c.                                                   j.                                                                              2-ethyl-3-vinyl-pyrazine                                                                           n.c.                                                   k.                                                                              2-methyl-3(5,6)-(pyrrolyl-1)-pyrazine                                                              n.c.                                                   l.                                                                              2-methyl-3-(thienyl-2)-pyrazine                                                                    n.c.                                                   m.                                                                              2-ethyl-pyrazine     J.Org.Chem.26, 3379                                                           (1961)                                                 n.                                                                              2-propyl-pyrazine    J.Org.Chem.26, 3379                                                           (1961)                                                 o.                                                                              2-isopropyl-pyrazine J.Org.Chem.26, 3379                                                           (1961)                                                 p.                                                                              2-vinyl-pyrazine     J.Org.Chem.26, 3379                                                           (1961)                                                 q.                                                                              2-isopropenyl-pyrazine                                                                             n.c.                                                   r.                                                                              2-methyl-3-vinyl-pyrazine                                                                          n.c.                                                (2)                                                                              a.                                                                              trimethyl-pyrazine   J.A.C.S. 72, 844(1950)                                 b.                                                                              2,6-dimethyl-3-ethyl-pyrazine                                                                      n.c.                                                   c.                                                                              2,5-dimethyl-3-ethyl-pyrazine                                                                      n.c.                                                   d.                                                                              2,5-dimethyl-3-propyl-pyrazine                                                                     n.c.                                                   e.                                                                              2,6-diethyl-3-methyl-pyrazine                                                                      n.c.                                                   f.                                                                              2,5-diethyl-3-methyl-pyrazine                                                                      n.c.                                                   g.                                                                              2,5-dimethyl-3-butyl-pyrazine                                                                      n.c.                                                   h.                                                                              2,3-dimethyl-5-isoamyl-pyrazine                                                                    n.c.                                                   i.                                                                              2,5-dimethyl-3-isoamyl-pyrazine                                                                    n.c.                                                   j.                                                                              2,3-diethyl-5-methyl-pyrazine                                                                      n.c.                                                (3)                                                                              a.                                                                              5-methyl-quinoxaline Ann.237, 336 (1887)                                    b.                                                                              2-methyl-quinoxaline Org.Synth.30,86 (1950)                                 c.                                                                              6-methyl-quinoxaline Ann. 237, 336 (1887)                                   d.                                                                              2,3-dimethyl-quinoxaline                                                                           Ber. 40, 4852 (1907)                                   e.                                                                              2-methyl-3-ethyl-quinoxaline                                                                       Ber. 22, 526 (1889)                                    f.                                                                              2,3-diethyl-quinoxaline                                                                            J.A.C.S.79,1712 (1957)                              (3)                                                                              g.                                                                              2-methyl-3-propyl-quinoxaline                                                                      J.Chem.Soc. 1946, 54                                   h.                                                                              2-methyl-3-isopropyl-quinoxaline                                                                   J.Chem.Soc. 1953, 2822                                 i.                                                                              2-methyl-3-butyl-quinoxaline                                                                       n.c.                                                   j.                                                                              2-methyl-3-isobutyl-quinoxaline                                                                    n.c.                                                   k.                                                                              2-methyl-3-amyl-quinoxaline                                                                        J.Chem.Soc. 1943, 322                                  l.                                                                              2-ethyl-quinoxaline  J.Chem.Soc. 1953, 2822                              (4)                                                                              a.                                                                              2-methyl-6-ethyl-pyrazine                                                                          n.c.                                                   b.                                                                              2-methyl-6-propyl-pyrazine                                                                         J.Org.Chem. 27, 1355                                                          (1962)                                                 c.                                                                              2,6-diethyl-pyrazine n.c.                                                   d.                                                                              2-methyl-6-vinyl-pyrazine                                                                          n.c.                                                (5)                                                                              a.                                                                              trimethyl-butyl-pyrazine                                                                           n.c.                                                   b.                                                                              trimethyl-isoamyl-pyrazine                                                                         n.c.                                                   c.                                                                              2,5-dimethyl-3,6-dipropyl-pyrazine                                                                 n.c.                                                   d.                                                                              2,5-dimethyl-3,6-diisopropyl-pyrazine                                                              n.c.                                                   e.                                                                              2,5-dimethyl-3,6-dibutyl-pyrazine                                                                  n.c.                                                   f.                                                                              2,5-dimethyl-3,6-diisobutyl-pyrazine                                                               n.c.                                                   g.                                                                              2,5-dimethyl-3,6-diamyl-pyrazine                                                                   n.c.                                                   h.                                                                              2,5-dimethyl-3,6-dihexyl-pyrazine                                                                  n.c.                                                   i.                                                                              2,3,5-trimethyl-6-hexyl-pyrazine                                                                   n.c.                                                   j.                                                                              2,5-dimethyl-3,6-diethyl-pyrazine                                                                  n.c.                                                (6)                                                                              a.                                                                              2-ethyl-5-methyl-pyrazine                                                                          n.c.                                                   b.                                                                              2-isopropyl-5-methyl-pyrazine                                                                      n.c.                                                   c.                                                                              2,5-diethyl-pyrazine n.c.                                                   d.                                                                              2-methyl-5-vinyl-pyrazine                                                                          n.c.                                            

Organoleptic evaluations are set out in TABLE VII below

The new compounds of this Group VII can be prepared as follows:

The 2,3-disubstitued pyrazines (formula (1)) can be obtained by a methodcomprising catalytically dehydrogenating with copper chromite thecorrespondingly substituted dihydropyrazines which, in turn, can beprepared by condensation of ethylene diamine with the correspondingalpha-diketones. By way of illustration the preparation of2-methyl-3-ethyl-pyrazine is described in more details.

(1) a. 2-Methyl-3-ethyl-pyrazine. In a 3-necked flask equipped with astirrer, means for cooling and a dropping funnel there was placed 150 g.of ethylene diamine in 500 ml. ether. After cooling to 0° C there wasslowly added with stirring a solution of 250 g. of ethyl methyl diketonein 500 ml. of ether. After the addition was complete, the temperaturewas allowed to rise to room temperature and the mixture was heated on awater bath for a few minutes. The material separated into 2 phases andthe water phase was discarded. The ether phase was dried with sodiumsulfate, the solvent was removed by evaporation and the residuedistilled under reduced pressure and an insert atmosphere. There wasobtained 192 g. of the dihydropyrazine (62% yield), boiling point61°-65°C./11 mm. Hg.

In an apparatus similar to that described by Bouveault in Bull IV, 3,119 (1908) the dihydro pyrazine was distilled under reduced pressureunder nitrogen atmosphere through a column containing copper chromite(Girdler G-13). The catalyst was heated to 300° C electrically and theeffluent was passed through a Widmer column to separate theunhydrogenated material.

The product was condensed, dried and redistilled; a 90% yield wasobtained of a product boiling at 57° C./10 mm. Hg.

The same method as used for compound (1) a. was applied for thepreparation of the following compounds:

    (1) b.                                                                             2-methyl-3-isobutyl-pyrazine                                                                     b.p. 74°/10 mm. Hg.                            (1) c.                                                                             2-methyl-3-propyl-pyrazine                                                                       b.p. 71°-72°/10 mm. Hg.                 (1) d.                                                                             2-methyl-3-isopropyl-pyrazine                                                                    b.p. 59°/10 mm. Hg.                            (1) e.                                                                             2-methyl-3-butyl-pyrazine                                                                        b.p. 83°-84°/9 mm. Hg.                  (1) f.                                                                             2-methyl-3-amyl-pyrazine                                                                         b.p. 98°/10 mm. Hg.                            (1) g.                                                                             2-methyl-3-hexyl-pyrazine                                                                        b.p. 113°-115°/9 mm.Hg.                 (1) i.                                                                             2,3-diethyl-pyrazine                                                                             b.p. 69°-71°/12 mm. Hg.             

1. j. 2-Ethyl-3-vinyl-pyrazine can be prepared from2-ethyl-3-methyl-pyrazine by the method described in J. Org. Chem. 27,1363 (1962). B.p. 75°-80°C./10 mm. Hg.

1. k. 2-Methyl-3(5,6)-(pyrrolyl-1)-pyrazine can be prepared as follows:N-Pyrrolyl-lithium is prepared by reacting 0.242 mole (15.4 g.) ofbutyllithium (as 15% suspension in hexane) with 0.22 mole (14.7 g.) ofpyrrole at -20° C. in the presence of 100 ml. of tetrahydrofuran. Thereis then added at room temperature a solution of 0.2 mole (25.6 g.) of3(5,6)-chloro-2-methyl-pyrazine [obtained by the method described in J.Org. Chem. 26, 2356 (1961)] in 75 ml. of tetrahydrofuran. The reactionmixture is refluxed for 5 days and subjected to the usual treatments forpurifying and isolating the reaction product which is then distilled.There is thus obtained 2-methyl-3(5,6)-N-pyrrolyl-pyrazine as a fractiondistilling at 120°-124°C./10Torr.

1. 1. 2-(Thienyl-2)-3-methyl-pyrazine is prepared as follows. A solutionof 0.36 g. (0.006 mole) of ethylene diamine in 3ml. of ether is cooledto 0°C. To this solution there is added slowly in a nitrogen atmospherea solution of 0.94 g. (0.006 mole) of (thienyl-2) methyl diketone(obtained by oxidation of 2-propionylthiophene with selenium dioxide) in3 ml. of absolute ether. The ether is gradually replaced by benzene, andwater is removed as an azeotropic mixture with the latter solvent. Thereaction product is fractionally distilled, and the fraction boiling at85°-105°C./0.003 mm. Hg. is redistilled through a copper chromite column(GIRDLER G-13) heated at 350° C. There is thus obtained2-(thienyl-2)-3-methyl-pyrazine of b.p. 94° C./0.03 mm. Hg.

1.q. 2-Isopropenyl-pyrazine is obtained from 2-ethyl-pyrazine by themethod described in J. Org. Chem. 27, 1363 (1962). It has the followingpeaks in the MS: 119 (100%), 120 (81%) and 67 (21%). 1. r.2-Methyl-3-vinyl-pyrazine is prepared from 2,3-diethylpyrazine by thesame method as used for compound (1) q. It has a b.p. of 66°-67° C./13mm. Hg.

2. b. 2,6-Dimethyl-3-ethyl-pyrazine is prepared by the addition of anethyl group at the 3-position of 2,6-dimethyl-pyrazine by thealkyl-lithium method described by Klein et al. in J.A.C.S. 73, 2949(1951). The resulting product has a b.p. of 64°-66° C. 8 mm. Hg.

2. c. 2,5-Dimethyl-3-ethyl-pyrazine is prepared by the addition of anethyl group at the 3-position of 2,5-dimethyl-pyrazine by thealkyl-lithium method described by Klein et al. (loc. cit.). Theresulting produuct has a b.p. of 63°-68° C./8 mm. Hg.

2. d. 2,5-Dimethyl-3-propyl-pyrazine is prepared by the addition of ann-propyl at the 3-position of 2,5-dimethyl-pyrazine by the alkyl-lithiummethod described by Klein et al. (loc. cit.). The product is identifiedby mass spectrometry. It has a b.p. of 80° C./10 mm. Hg.

2. e. 2,6-Diethyl-3-methyl-pyrazine is prepared by the introduction of amethyl group into the 3-position of 2,6-diethyl-pyrazine by the methodof Klein et al. (loc. cit.). The product has a b.p. of 91°-92°C./13 mm.Hg.

2. f. 2,5-Diethyl-3-methyl-pyrazine is prepared by the introduction of amethyl group into the 3-position of 2,5-diethyl-pyrazine by the methodKlein et al. (loc. cit.). The product was isolated by gas chromatographyand was identified by mass spectrometry.

2. g. 2,5-Dimethyl-3-butyl-pyrazine is prepared by introducing a butylgroup into the 3-position of 2,5-dimethyl-pyrazine by the method Kleinet al. (loc. cit.). The resulting product has a b.p. of 91° C./9 mm. Hg.

2. h. 2,3-Dimethyl-5-isoamyl-pyrazine is prepared by introducing anisoamyl group into the 5-position of 2,3-dimethyl-pyrazine by the methodof Klein et al. (loc. cit.). The product is identified by massspectrometry.

2. i. 2,5-Dimethyl-3-isoamyl-pyrazine is prepared by introducing anisoamyl group into the 3-position of 2,5-dimethyl-pyrazine by the methodof Klein et al. (loc. cit.). The product has a b.p. of 110°-120°C./13mm. Hg.

2. j. 2,3-Diethyl-5-methyl-pyrazine is prepared by the method describedfor the preparation of compound (1) a. in Group VII, using1,2-diamino-propane instead of ethylene diamine and dipropionyl as theα-diketone. The product has a b.p. of 79°-80° C./12 mm. Hg.

3. i. 2-Methyl-3-butyl-quinoxaline is obtained by the same method ascompound (3) d. of Group VII. It has a b.p. of 153°C./9 mm. Hg.

3. j. 2-Methyl-3-isobutyl-quinoxaline is obtained by the same method ascompound (3) e. of Group VII. It has a m.p. of 94°-95°C.

4. a. 2-Methyl-6-ethyl-pyrazine was obtained by the alkylation of2,6-dimethyl-pyrazine by the method described by Levine and Behun in J.Org. Chem. 26, 3379 (1961). It has a boiling point of 54°-57°C./11 mm.Hg.

4. c. 2,6Diethyl-pyrazine was obtained by subjecting compound (4) a. toa second alkylation by the procedure described above. It has a boilingpoint of 70° at 10 mm. Hg.

4. d. 2-Methyl-6-vinyl-pyrazine is obtained by starting with2,6-dimethyl-pyrazine and following the method of Levine et al. reportedin J.Org.Chem. 27, 1363 (1962). It has a b.p. of 74°-75°/22 mm. Hg.

5. a. 2,3,5-Trimethyl-6-butyl-pyrazine was prepared by introducing abutyl group into the 6-position of 2,3,5-trimethylpyrazine by the methodof Klein et al. (loc.cit.). The product was isolated by gaschromatography and identified by mass spectrometry.

5. b. 2,3,5-Trimethyl-6-isoamyl-pyrazine was prepared by introducing anisoamyl group into the 6-position of 2,3,5-trimethyl-pyrazine by themethod of Klein et al. (loc.cit.). The product had a b.p. of 80°C./10mm. Hg.

5. c. 2,5-Dimethyl-3,6-dipropyl-pyrazine was prepared by first forming3-oximino-2-hexanone by reacting 2-hexanone with nitrosyl chlorideaccording to the method of BOUVEAULT, Bull. [3] 31, 1163 (1904). Theautocondensation of two molecules of the imino-ketone in the presence ofzinc and acetic acid [according to the method described in Chimia 11,310 (1957)] yielded 2,5-dimethyl-3,6-dipropyl-pyrazine which had a b.p.of 109°-110°C./10 mm. Hg.

5. d. 2,5-Dimethyl-3,6-diisopropyl-pyrazine was prepared by firstforming 4-methyl-3-oximino-2-pentanone by reacting 4-methyl-2-pentanonewith nitrosyl chloride according to the method of Bouveault, Bull. [3]31, 1163 (1904). The autocondensation of two moles of the imino-ketonein the presence of zinc and acetic acid [according to the methoddescribed in Chimia 11, 310 (1957)] yielded2,5-Dimethyl-3,6-diisopropyl-pyrazine which had a b.p. of 91°C./8 mm.Hg.

5. e. 2,5-Dimethyl-3,6-dibutyl-pyrazine was prepared by first forming3-oximino-2-heptanone by reacting 2-heptanone with nitrosyl chlorideaccording to the method of BOUVEAULT, Bull. [3] 31, 1163 (1904) Theautocondensation of 2 moles of the imino-ketone in the presence of zincand acetic acid [according to the method described in Chimia 11, 310(1957)] yielded 2,5-dimethyl-3,6-dibutyl-pyrazine which had a b.p. of18° C./0.002 mm. Hg.

5. f. 2,5-Diimethyl-3,6-diisobutyl-pyrazine was prepared by firstforming 5-methyl-3-oximino-2-hexanone by reacting 5-methyl-2-hexanonewith nitrosyl chloride according to the method of BOUVEAULT (loc.cit.).The autocondensation of two moles of the imino-ketone in the presence ofzinc and acetic acid [according to the method described in Chimia 11,310 (1957)] yielded 2,5-dimethyl-3,6-diisobutyl-pyrazine which had ab.p. of 69°-70°C./0.01 mm. Hg.

5. g. 2,5-Dimethyl-3,6-diamyl-pyrazine was prepared by first forming3-oximino-2-octanone by reacting 2-octanone with nitrosyl chlorideaccording to the method of BOUVEAULT (loc.cit.). The autocondensation oftwo moles of the imino-ketone in the presence of zinc and aceticacid[according to the method described in Chimia 11, 310 (1957)] yielded2,5-dimethyl-3,6-diamyl-pyrazine which has a b.p. of 78°C./0.03 mm. Hg.

5. h. 2,5-Dimethyl-3,6-dihexyl-pyrazine was prepared by first forming3-oximino-2-nonanone by reacting 2-nonanone with nitrosyl chlorideaccording to the method of BOUVEAULT (loc.cit.). The autocondensation oftwo moles of the imino-ketone in the presence of zinc and acetic acid[according to the method described in Chimia 11, 310 (1957)] yielded2,5-dimethyl-3,6-dihexyl-pyrazine which had a b.p. of 112°-120°C./0.01mm. Hg.

5. i. 2,3,5-Trimethyl-6-hexyl-pyrazine was prepared by introducing ahexyl group into the 6-position of 2,3,5-trimethyl-pyrazine by themethod of Klein et al. (loc.cit.). The product had a b.p. of89°-91°C./0.2 mm. Hg.

5. j. 2,5-Dimethyl-3,6-diethyl-pyrazine is prepared by alkylation of2,5-dimethyl-3-ethyl-pyrazine according to the alkyl-lithium methoddescribed by Klein et al. [J.A.C.S. 73, 2949 (1951)]. It has a b.p. of83°-85°C./8 mm. Hg.

6. a. 2-Ethyl-5-methyl-pyrazine was prepared by alkylation of2,5-dimethyl-pyrazine following the procedure of Levine and Behundescribed in J.Org.Chem. 26, 3379 (1961). It has a boiling point of60°C./11 mm. Hg.

6. b. 2-Isopropyl-5-methyl-pyrazine was produced in the preparation ofcompound (6) a. as a by-product and was separated from the reactionmixture by gas chromatography. Identification was confirmed by massspectrometry.

6. c. 2,5-Diethyl-pyrazine was obtained by subjecting compound (6) a. toa second alkylation by the procedure given for compound (6) a. above. Itboils at 64°C. at 12 mm. Hg.

6. d. 2-Methyl-5-vinyl-pyrazine was prepared by the method of Levine etal. described at J.Org.Chem. 27, 1363 (1962), starting from2,5-dimethyl-pyrazine. It has a boiling point of 65°-66°C./12 mm. Hg.

VIII. - Aliphatic and Aromatic Alochols

This group comprises compounds having the general formula: ##EQU1##wherein 1. R₁ is hydrogen or an alkyl group, e.g. methyl, ethyl, propyl;and R₂ is an alkyl group having at least 4 carbon atoms, e.g. from 4 to9 carbon atoms; or

2. R₁ is hydrogen or an alkyl group, e.g. comprising from 1 to 6 carbonatoms; and R₂ is an aryl group, e.g. phenyl; an aralkyl group, e.g.benzyl, phenylethyl; phenylpropyl; or an aralkenyl group, e.g. styryl,cinnamyl.

Compounds representative of this group include for instance:

    (1) a. n-amylalcohol         c.a.                                             b.     isoamylalcohol        c.a.                                             c.     n-hexanol             c.a.                                             d.     n-heptanol            c.a.                                             e.     n-octanol             c.a.                                             f.     n-nonanol             c.a.                                             g.     n-decanol             c.a.                                             h.     2-heptanol            c.a.                                             i.     3-octanol             c.a.                                             (2) a. phenylethan-1-ol      c.a.                                             b.     phenylpropan-1-ol     c.a.                                             (2) c. cinnamyl alcohol      c.a.                                             d.     phenyl methyl carbinol                                                                              c.a.                                             e.     benzyl methyl carbinol                                                                              c.a.                                             f.     benzyl ethyl carbinol c.a.                                             g.     benzyl butyl carbinol n.c.                                             h.     benzyl amyl carbinol  n.c.                                             i.     benzyl isoamyl carbinol                                                                             n.c.                                             j.     benzyl hexyl carbinol n.c.                                         

The new compounds of this Group VIII can be prepared as follows:

2. g. Benzyl butyl carbinol. To a solution of 1.05 mole ofbutyl-magnesium bromide in 400 ml. of ether there is added a solution of1 mole (120 g.) of phenylacetaldehyde in 300 ml. of ether at -8° to -12°C. within 3 to 4 hours. The reaction mixture is heated to about 20° C.and worked up by conventional methods. Distillation of the crudereaction product yields 99 g. of benzyl butyl carbinol of b.p. 88°-91°C./0.06 Torr; d₄ ²⁰ = 0.9485; n_(D) ²⁰ = 1.5059.

The same method is used for preparing:

2. h. Benzyl amyl carbinol, b.p. 81° C./0.01 Torr.

2. i. Benzyl isoamyl carbinol, b.p. 142°-143° C./13 Torr; d₄ ²⁰ 320.9377 n_(D) ²⁰ = 1.5009.

2. j. Benzyl hexyl carbinol, b.p. 95°C./0.01 Torr; d₄ ²⁰ = 0.9339; n_(D)³⁴ 20 = 1.4997.

Organoleptic evaluation data are listed in TABLE VIII below.

IX. -- Furan Ethers

The compounds of this group have the general formula: ##SPC22##

wherein R₁ and R₂ are hydrogen; alkyl, e.g. methyl, ethyl; aryl, e.g.phenyl, alkylphenyl; furfuryl, or alkylfurfuryl groups.

Compounds representative of this group include the following:

    (1) a.                                                                            furfuryl methyl ether                                                                             Ber. 56. 1004 (1923)                                  b.  furfuryl ethyl ether                                                                              Ber. 56. 1004 (1923)                                  c.  furfuryl phenyl ether                                                                             Bull. 1938. 1151                                      d.  5-methyl-furfuryl furfuryl ether                                                                  n.c.                                                  e.  difurfuryl ether    Am.Soc. 49. 1066 (1927)                           

1. d. 5-Methyl-furfuryl furfuryl ether was prepared by the proceduredescribed by J. E. Zanetti in J.Am.Chem.Soc. 49, 1066 (1927) for thedifurfuryl ether, starting with 5-methyl-furfuryl bromide (Compt.Rend.222, 1441 (1946)) instead of furfuryl bromide of Zanetti. The productwas isolated by ether extraction of the crude mixture after havingdiluted with water. For purification the ether extract was distilledtwice -- b.p. 68°-70° C. at 0.01 mm./Hg vacuum. The product was aviscous colourless liquid, darkening rapidly on contact with air.

Organoleptic evaluations are tabulated in TABLE IX.

X -- Thiophene Ethers

This group of compounds are described by the structural formula:##SPC23##

wherein R is an alkyl group, phenyl, alkylphenyl, furfuryl,alkylfurfuryl, or thenyl group, and includes for example:(1) a. thenylmethyl ether J.A.C.S. 49. 1066(1927) J.A.C.S. 50. 1960(1928)b. dithenylether n.c.c. furfuryl thenyl ether n.c.

The new compounds of this group were prepared as follows:

1. b. Dithenyl ether. To a suspension of 1.32 g. (0.01 mole) ofchloromethylthiophene [obtained by the method of F. F. BLICKE, J.A.C.S.64, 477 (1942)] and 1.2 g. (0.02 mole) of powdered potassium hydroxidein 10 ml. of ether there is added a solution of 3.5 g. (0.03 mole) ofthenyl alchohol in 10 ml. of ether. The reaction mixture is stirred for1 hour at room temperature, then refluxed for 30 minutes and finallyallowed to stand over night. After filtration the ethereal solution isconcentrated and the residue fractionally distilled. There is obtained0.22 g. (10%) of dithenyl ether having a b.p. of 99° C./0.01 mm. Hg. anda m.p. of 36.5°.

1. c. Furfuryl thenyl ether is obtained by the same method as used forpreparing compound (1) b., but using furfuryl alcohol instead of thenylalcohol. The product thus obtained had a b.p. of 50° C/0.01 mm. Hg.

Organoleptic evaluation data on representatives of this group ofcompounds are set out in TABLE X below.

XI -- Thiazole Alcohols

Compounds of this group have the following structural formula: ##SPC24##

wherein R is an alkyl group, e.g. containing from 1 to 4 carbon atoms,or an alkenyl group, e.g. vinyl.

Representative compounds include the following:

    (1)  a.     methyl (4-methyl-thiazolyl-2) carbinol                                                                  n.c.                                         b.     ethyl (4-methyl-thiazolyl-2) carbinol                                                                   n.c.                                         c.     vinyl (4-methyl-thiazolyl-2) carbinol                                                                   n.c.                                         d.     isobutyl (4-methyl-thiazolyl-2) carbinol                                                                n.c.                                

The new compounds of this Group X can be prepared as follows:

1. a. Methyl (4-methyl-thiazolyl-2) carbinol was prepared by startingfrom 4-methyl-thiazole and substituting the hydrogen atom in the2-position by lithium by reaction with butyl-lithium. The resultingmetal-organic compounds was reacted with acetaldehyde [cf. J.A.C.S. 74,6260 (1952)]. The resulting product has a b.p. of 102°-103° C./9 mm. Hg.

1. b. Ethyl (4-methyl-thiazolyl-2) carbinol was prepared by startingfrom 4-methyl-thiazole and substituting the hydrogen atom in the2-position by lithium by reaction with butyl-lithium. The resultingmetal-organic compound was reacted with propionaldehyde [cf. J.A.C.S.74, 6260 (1952)]. The resulting product had a b.p. of 110°-115° C./9 mm.Hg. and a m.p. of 67°-72° C.

1. c. Vinyl (4-methyl-thiazolyl-2) carbinol was prepared by startingfrom 4-methyl-thiazole and substituting the hydrogen atom in the2-position by lithium by reaction with butyl-lithium. The resultingmetal-organic compound was reacted with acrolein [cf. J.A.C.S. 74, 6260(1952)]. The resulting product had a b.p. of 66° C./0.005 mm.Hg.

1. d. Isobutyl (4-methyl-2-thiazolyl) carbinol was prepared by startingfrom 4-methyl-thiazole and substituting the hydrogen atom in the2-position by lithium by reaction with butyl-lithium. The resultingmetal-organic compound was reacted with isovaleraldehyde [cf. J.A.C.S.74, 6260 (1952)]. The resulting product had a b.p. of 94° C/0.1 mm. Hg.

Organoleptic evaluations are set out in TABLE XI below.

XII -- Pyridine Ethers and Alcohols

Compounds of this group are found to have the following general formula:##SPC25##

wherein R₁ is hydrogen or an alkoxy group, R₂ is hydrogen or an alkylgroup, and n is 0, 1 or 2. Examples of this group include:

    (1)  a.     2-methoxy-pyridine        c.a.                                         b.     2-butoxy-pyridine         n.c.                                         c.     2-methoxymethyl-pyridine  c.a.                                         d.     2-methoxymethyl-6-methyl-pyridine                                                                       c.a.                                         e.     2-hydroxymethyl-pyridine  c.a.                                         f.     3-hydroxymethyl-pyridine  c.a.                                         g.     4-hydroxymethyl-pyridine  c.a.                                         h.     2-hydroxymethyl-6-methyl-pyridine                                                                       c.a.                                         i.     2-(2-hydroxyethyl)-pyridine                                                                             c.a.                                         j.     2-(2-ethoxyethyl)-pyridine                                                                              c.a.                                

1. b. 2 -Butoxy-pyridine was prepared according to the method describedin J.A.C.S. 69, 1803 (1947) by condensing 0.17 mole of 2-bromo-pyridinewith 0.195 mole of sodium butoxide. By distillation of the reactionproduct there were obtained 15 g. of 2-butoxy-pyridine distilling at 78°C./10 mm.Hg. n_(D) ²³ = 1.4880; d₄.sup. 23,4 = 0.9723.

Organoleptic evaluations are set out in TABLE XII below.

XIII -- Pyrazine Ethers and Alcohols

Compounds of this group are represented by the general formula:##SPC26##

wherein R represents hydrogen or an alkyl group and n is 0, 1 or 2.

Examples of compounds covered by this formula are:

    (1)                                                                              a.                                                                              2-hydroxymethyl-pyrazine                                                                   J.Org.Chem. 28. 1898 (1963)                                    b.                                                                              2-methoxymethyl-pyrazine                                                                   n.c.                                                           c.                                                                              2-ethoxymethyl-pyrazine                                                                    n.c.                                                    

Compounds (1) b. and (1) c. were prepared by reacting2-chloromethyl-pyrazine with the corresponding sodium alkoxide accordingto the same method as used for the preparation of sulfides [cf.HOUBEN-WEYL, 4th edition, vol. 9, 97 (1955)]. The products thus obtainedhad the following boiling points:

compound (1) b.: 51° C./8 mm. Hg.;

compound (1) c.: 75° C./8 mm. Hg.

Organoleptic evaluations are set out in TABLE XIII below.

XIV -- Benzofuran Carbonyl Compounds

This group of compounds has the following general formula: ##SPC27##

wherein R₁ and R₂ may be hydrogen or alkyl.

Examples of compounds included in this definition are:(1) a.benzofuran-2-aldehyde Bull. 1962. 1875 b. 2-acetyl-benzofuranJ.A.C.S.73. 754 (1951) c. 7-methyl-benzofuran-2-aldehyde n.c.

1. c. 7 -Methyl-benzofuran-2-aldehyde was prepared by formylating7-methyl-benzofuran according to the same method as used for thepreparation of benzofuran-2-aldehyde. The product thus obtained has thefollowing ion peaks in its mass spectrum: 160 (100%), 159 (62%) and 131(33%).

Organoleptic evaluations are set out in TABLE XIV below.

XV -- Thiophene Aldehydes

Compounds of this group have the general formulae: ##SPC28##

wherein R is hydrogen, or an alkyl or thenyl group; and ##SPC29##

wherein R₁ and R₂ represent hydrogen or alkyl.

Compounds in this group include for instance:(1) a. Thiophene-2-aldehydec.a. b. 5-methyl-thiophene-2-aldehyde Org.Syn. 36, 74 (1956) c.3-methyl-thiophene-2-aldehyde *b.p. 88-89°C./10 mm.Hg. d.5-propyl-thiophene-2-aldehyde *b.p. 64-65°C./0.002 mm.Hg. e.5-thenyl-thiophene-2-aldehyde *m.p. 31-32°C.*prepared according to thesame method as used for compound (1) b.(2) a. benzothiophene-2-aldehydeJ.A.C.S.74, 2935 (1932)(2) b. 2-acetyl-benzothiophene Compt.Rend.234,736 (1952)

Organoleptic evaluations are set out in TABLE XV below.

XVI -- Pyrrole Aldehydes

Compounds of this group have the structural formula ##SPC30##

wherein R is an alkyl, furfuryl or thenyl group.

Representative compounds include, for example:

    (1)                                                                              a.                                                                              1-ethyl-pyrrole-2-aldehyde                                                                       n.c.                                                     b.                                                                              1 butyl-pyrrole-2-aldehyde                                                                       Helv. 13. 349 (1930)                                     c.                                                                              1-butyl-pyrrole-3-aldehyde                                                                       n.c.                                                     d.                                                                              1-amyl-pyrrole-2-aldehyde                                                                        n.c.                                                     c.                                                                              1-amyl-pyrrole-3-aldehyde                                                                        n.c.                                                     f.                                                                              1-α-methylbutyl-pyrrole-2-aldehyde                                                         n.c.                                                     g.                                                                              1-α-methylbutyl1pyrrole-3-aldehyde                                                         n.c.                                                     h.                                                                              1-furfuryl-pyrrole-2-aldehyde                                                                    Helv. 13, 349 (1930)                                     i.                                                                              1-furfuryl-pyrrole-3-aldehyde                                                                    n.c.                                                     j.                                                                              1-thenyl-pyrrole-2-aldehyde                                                                      n.c.                                                     k.                                                                              1-isoamyl-pyrrole-2-aldehyde                                                                     Helv. 13, 349 (1930)                              

The new compounds of this group XVI can be prepared as follows:

1. a. 1-Ethyl-pyrrole-2-aldehyde was prepared from 1-ethyl-pyrrole[obtained by the method described in Helv. 10, 387 (1927)] byintroducing a formaldehyde group following the technique described inOrg.Synth. 36, 74 (1956). The product boiled at 73°-75° C./7 mm. Hg.

1. c. 1 -Butyl-pyrrole-3-aldehyde was prepared by the same method asused for compound (1) a. It has a b.p. of 148°-150° C./11 mm. Hg.

1. d. 1 -Amyl-pyrrole-2-aldehyde was prepared by the same method as usedfor compound (1) a. It has a b.p. of 111°-112° C./11 mm. Hg.

1. e. 1 -Amyl-pyrrole-3-aldehyde was prepared by the same method as usedfor compound (1) a. It has a b.p. of 155°-160° C./11 mm.Hg.

1. f. 1 -α-Methylbutyl-pyrrole-2-aldehyde was prepared by the samemethod as used for compound (1) a. It has a b.p. of 103°-105° C./11 mm.Hg.

1. g. 1 -α-Methylbutyl-pyrrole-3-aldehyde was prepared by the samemethod as used for compound (1) a. It has a b.p. of 150° C./11 mm. Hg.

1. h. 1 -furfuryl-pyrrole-2-aldehyde was prepared starting with1-furfuryl-pyrrole described by Reichstein in Helv. 15, 1450 (1932) aswell as Gianturco et al. in Tetrahedron 20, 1763 (1964). The aldehydegroup was introduced by the Vilameyer reaction (e.g. by the methoddescribed in Bull. 1962, 1989). A small amount of the corresponding3-aldehyde is obtained as a byproduct and can be separated by fractionaldistillation. The 2-aldehyde boils at 139°-140° C./12 mm. Hg. and is aviscous colorless oil. The 3-aldehyde has a b.p. of 190° C./12 mm. Hg.

1. j. 1 -Thenyl-pyrrole-2 -aldehyde was prepared by the same method asused for compound (1) h. It has a b.p. of 98° C./0.005 mm. Hg.

The organoleptic evaluations are shown in TABLE XVI below.

XVII -- Pyrazine Carbonyl Compounds

Compounds of this group have the general formula: ##SPC31##

wherein R is hydrogen or an alkyl group and n is 0 or 1. Examples ofthis group include:(1) a. 2-formyl-pyrazine C.A. 58. 101806 (1963) b.2-acetyl-pyrazine J.A.C.S. 74. 3621 (1952) c. 2-acetonyl-pyrazineJ.Org.Chem.23. 406 (1958)

Organoleptic evaluations are tabulated in TABLE XVII below.

XVIII -- Aliphatic and Aromatic Ketones

The compounds of this group are defined by the following generalformula:

     R.sub.1 --CO--R.sub.2                                     (1

wherein R₁ is an alkyl group having from 1 to 3 carbon atoms and R₂ isan alkyl group having from 3 to 11 carbon atoms, or a phenyl or benzylgroup.

Examples of compounds corresponding to this definition are as follows:

    (1)  a.    methyl amyl ketone                                                                            c.a.                                                    b.    methyl hexyl ketone                                                                           c.a.                                                    c.    methyl heptyl ketone                                                                          c.a.                                                    d.    methyl octyl ketone                                                                           c.a.                                                    e.    methyl nonyl ketone                                                                           c.a.                                                    f.    methyl decyl ketone                                                                           c.a.                                                    g.    methyl undecyl ketone                                                                         c.a.                                                    h.    ethyl butyl ketone                                                                            c.a.                                                    i.    ethyl amyl ketone                                                                             c.a.                                                    j.    dipropyl ketone c.a.                                               (1)  k.    propyl isopropyl ketone                                                                       J.A.C.S. 63, 3163 (1941)                                l.    di-isopropyl ketone                                                                           J.A.C.S. 59, 1826 (1937)                                m.    acetophenone    c.a.                                                    n.    propiophenone   c.a.                                                    o.    isopropyl phenyl ketone                                                                       c.a.                                                    p.    methyl benzyl ketone                                                                          c.a.                                                    q.    ethyl benzyl ketone                                                                           c.a.                                           

Organoleptic evaluations are tabulated in TABLE XVIII below.

XIX -- Furan Ketones

This family of compounds have the following general formula: ##SPC32##

wherein n is 0, 1 or 2 and wherein R₁ is hydrogen or methyl, and R₂ isalkyl.

Representative examples of compounds in this group include:

    (1)                                                                              a.                                                                              2-acetyl-furan    c.a.                                                      b.                                                                              2-propionyl-furan J.A.C.S. 72, 3695 (1950)                                  c.                                                                              2-butyryl-furan   J.A.C.S. 72, 3695 (1950)                                  d.                                                                              2-valeryl-furan   J.A.C.S. 72, 3695 (1950)                                  e.                                                                              5-methyl-2-acetyl-furan                                                                         J.A.C.S. 72, 3695 (1950)                                  f.                                                                              5-methyl-2-propionyl-furan                                                                      J.A.C.S. 72, 3695 (1950)                                  g.                                                                              furfuryl methyl ketone                                                                          Ber. 76, 192 (1943)                                       h.                                                                              furfuryl ethyl ketone                                                                           J.Org.Chem. 15, 8 (1950)                                  i.                                                                              (5-methyl-furfuryl) methyl ketone                                                               n.c.                                                      j.                                                                              (5-methyl-furfuryl) ethyl ketone                                                                n.c.                                                   (1)                                                                              k.                                                                              4-furyl-2-butanone                                                                              J.A.C.S. 72, 3695 (1950)                                  l.                                                                              4-(5-methylfuryl)-2-butanone                                                                    Ber. 76, 192 (1943)                                       m.                                                                              1-(5-methylfuryl)-3-pentanone                                                                   n.c.                                               

The new compounds of this group can be prepared as follows:

1. i. (5 -Methyl-furfuryl) methyl ketone was prepared according to theprocedure described by Hass et al. in J.Org.Chem. 15, 8 (1950) bycondensing 5-methyl-furfuryl-aldehyde with nitroethane. The product hasa b.p. of 75° C./10 mm. Hg.

1. j. (5 -Methyl-furfuryl) ethyl ketone was prepared by the same methodas used for compound (1) i., except that 1-nitropropane was used insteadof nitroethane. The product has a b.p. of 97°-100° C./15 mm. Hg.

1. m. 1-(5 -Methylfuryl)- 3-pentanone was prepared by the methoddescribed in Ber. 76, 192 (1943). It has a b.p. of 101°-102° C./11 mm.Hg.

Organoleptic evaluation data are set out in TABLE XIX below.

XX -- Thiophene Ketones

Compounds of this group which have been found to have utility in theconcept of the instant invention have the following general formulae:##SPC33##

wherein n is 0 or 1, R₁ is hydrogen or alkyl and R₂ is alkyl; and##SPC34##

wherein n is 0 or 1.

Representative compounds include:(1) a. 2-acetyl-thiophene J.A.C.S. 72,3695 (1950)b. 3-methyl-2-acetyl-thiophene J.A.C.S. 72, 3695 (1950)c.4-methyl-2-acetyl-thiophene J.A.C.S. 72, 3695 (1950)d.3-methyl-2-propionyl-thiophene J.A.C.S. 72, 3695 (1950)e.5-methyl-2-propionyl-thiophene J.A.C.S. 72, 3695 (1950)f.2-butyryl-thiophene J.A.C.S. 72, 3695 (1950)g.5-methyl-2-acetyl-thiophene J.A.C.S. 72, 3695 (1950)h.2-propionyl-thiophene J.A.C.S. 72, 3695 (1950)i.2-acetylmethyl-thiophene C.A. 51. 10,509c (1957)(2) a.5,5'-diacetyl-dithienyl-2,2'-methane J.A.C.S. 73, 1270 (1951)b.5,5'-diacetyl-dithienyl-2,2' J.A.C.S. 78. 1958 (1956)

Organoleptic evaluation data are set out in Table XX below.

XXI -- Pyrrole Ketones

Compounds of this group have the general formulae: ##SPC35##

wherein X is oxygen or sulfur, R₁ is an alkyl group and R₂ is hydrogenor an alkyl group; ##SPC36##

wherein R is an alkyl group; ##SPC37##

wherein R₁ is hydrogen or an alkyl group and R₂ is an alkyl group;##SPC38##

wherein R₁, R₂ and R₄ represent hydrogen or alkyl groups and R₃ is analkyl group.

Compounds which are representative of this group include:

    (1) a.                                                                            1-furfuryl-2-acetyl-pyrrole                                                                     n.c.                                                    b.  1-thenyl-2-acetyl-pyrrole                                                                       J.A.C.S. 85. 2859 (1963)                                c.  1-thenyl-3-acetyl-pyrrole                                                                       J.A.C.S. 85. 2859 (1963)                                (2) a.                                                                            1-acetyl-pyrrole  Chem. & ind. 1965. 1426                                 b.  1-propionyl-pyrrole                                                                             Ber. 89, 1938 (1956)                                    (3) a.                                                                            2-methyl-5-acetyl-pyrrole                                                                       c.a.                                                    b.  1,2-dimethyl-5-acetyl-pyrrole                                                                   n.c.                                                    (4) a.                                                                            2,5-dimethyl-3-acetyl-pyrrole                                                                   Beilstein XXI, 277 (1935)                               b.  1-methyl-3-acetyl-pyrrole                                                                       n.c.                                                

The new compounds included in this group can be prepared as follows:

1. a. 1-furfuryl-2-acetyl-pyrrole was prepared starting from1-furfuryl-pyrrole described by Reichstein in Helv. 15, 1450 (1932) aswell as Gianturco et al. in Tetrahedron 207, 1763 (1964). Acetylation byreaction of the Grignard intermediate with acetyl chloride [cf. Chem.Ber. 47, 1416 (1914)] led to the desired ketone. (A small amount of the3-isomer was also obtained, separable by fractional distillation). Theproduct boils at 100°-102° C./0.03 mm Hg. and crystallizes on standing.Recrystallization from a mixture of methylene dichloride and petroleumether gave a white crystalline product with a m.p. of 42°-43° C.

3. b. 1,2-Dimethyl-5-acetyl-pyrrole was obtained by acetylating1,2-dimethylpyrrole according to the method described in Ber. 47, 1416(1914) [cf. also J.A.C.S. 85, 2859 (1963)]. The product has a b.p. of102°-106° C./10 mm Hg.

4. b. 1-Methyl-3-acetyl-pyrrole was obtained as a by-product in thesynthesis of 1-methyl-2-acetyl-pyrrole according to the method describedin Ber. 47, 1416 (1914). The product has a b.p. of 130°-132° C./12 mm.Hg.

Evaluation data are set out in TABLE XXI below.

XXII -- Thiazole Carbonyl Compounds

Compounds of this group have the following general formula: ##SPC39##

wherein R₁ and R₂ are hydrogen or alkyl groups.

Representative compounds of this group are:(1) a.4-methyl-2-acetyl-thiazole Bull. 20, 702 (1953)b.4-methyl-2-propionyl-thiazole n.c.c. 5-methyl-2-acetyl-thiazole Bull.20, 702 (1953)d. 4-methyl-2-butyryl-thiazole n.c.e.4-methyl-2-formyl-thiazole n.c.

The new compounds included in this group can be prepared as follows:

1. b. 4-Methyl-2-propionyl-thiazole was prepared according to the methoddescribed in Bull. 20, 702 (1953) by reacting 4-methyl-thiazole withethyl-magnesium bromide and acylating the obtained Grignard intermediatewith propionyl chloride. The product has a b.p. of 83°-88° C./9 mm. Hg.

1. d. 4-Methyl-2-butyryl-thiazole was prepared by the same method ascompound (1) b, but using butyric anhydride as the acylating agent. Theproduct has a b.p. of 110°-115° C./8 mm. Hg.

1. e. 4-Methyl-2-formyl-thiazole was prepared by oxidizing2-hydroxymethyl-4-methyl-thiazole with chromic acid in a sulfuric acidmedium according to the method described in J.A.C.S. 53, 1470 (1931).The product was identified by mass spectrometry (peaks M/e and relativeintensity): 71 (100%), 127 (97%) and 72 (48%).

Organoleptic evaluation data are set out in TABLE XXII below.

XXIII -- Pyridine Carbonyl Compounds

Compounds of this group have the general formula: ##SPC40##

wherein R₁ represents hydrogen, an alkyl group or a phenyl group, R₂represents hydrogen, an alkyl group or an acyl group and n is 0, 1 or 2.

Representative compounds include:

    (1) a. 2-acetyl-pyridine   c.a.                                               b.     6-methyl-2-acetyl-pyridine                                                                        c.a.                                               c.     3-acetyl-pyridine   c.a.                                               d.     4-acetyl-pyridine   c.a.                                               e.     pyridine-2-aldehyde c.a.                                               f.     pyridine-3-aldehyde c.a.                                               (1) g. pyridine-4-aldehyde c.a.                                               h.     6-methyl-pyridine-2-aldehyde                                                                      c.a.                                               i.     2-benzoyl-pyridine  c.a. -j. 3-benzoyl-pyridine c.a.                   k.     4-benzoyl-pyridine  c.a.                                               l.     2,6-diacetyl-pyridine                                                                             c.a.                                               m.     4-(γ-pyridyl)-butan-2-one                                                                   n.c.                                           

The new compound, 4-(γ-(pyridyl)-butan-2-one, was prepared as follows:

8 ml. of 2-n NaOH solution were added to a mixture of 10.8 g. (0.1 mole)of pyridine-4-aldehyde, 100 ml. of water and 10 ml. of acetone at12°-15° C. After a reaction time of 3 minutes the reaction mixture wasneutralized with 10% aqueous acetic acid, saturated with NaCl andextracted with ether. After removal of the ether the residue wasdistilled. There were obtained 8.4 g. of 4-(γ-pyridyl)-3-buten-2-one asa yellow oil of b.p. 135°-138° C./ 0.07 Torr. 5.24 g. of this productwere dissolved in 30 ml. of ethanol and hydrogenated in the presence of4 g. of Ni-catalyst. Distillation of the reaction product yielded4-(γ-pyridyl)-butan-2-one of b.p. 83°-85° C./0.05 Torr; n₄ ²⁷ = 1.047;n_(D) ²⁷ = 1.516.

Organoleptic evaluation data are set out in Table XXIII below.

XXIV -- Alpha-Diketones

Compounds of this group which have been found to have utility in theconcept of this invention are of the formulae:

    CH.sub.3 COCOR                                             1

    C.sub.2 H.sub.5 COCOR                                      2

wherein R is an alkyl group or a phenyl group.

Compounds representative of this group include:

    (1)                                                                              a.                                                                              acetylbutyryl  J.Chem.Soc. 1946, 56                                         b.                                                                              acetylisobutyryl                                                                             Ber. 22, 2121 (1889)                                         c.                                                                              acetylisovalerianyl                                                                          Ber. 22, 2122 (1889)                                         d.                                                                              acetylcaproyl  J.pr.Ch.[2] 58, 402 (1898)                                                    n.sub.D.sup.20 = 1.4214; d.sub.4.sup.20 = 0.9183             e.                                                                              acetylbenzoyl  c.a. (British Drug House)                                    f.                                                                              5-methyl-heptanedione-2,3                                                                    n.c.                                                         g.                                                                              5-methyl-octanedione-2,3                                                                     n.c.                                                         h acetylvalerianyl                                                                             n.c.                                                         i.                                                                              acetylheptanoyl                                                                              n.c.                                                      (2)                                                                              a.                                                                              dipropionyl    Bull.[3], 31, 629,650 (1906)                                 b.                                                                              heptane-3,4-dione                                                                            Bull.[3], 31, 1174 (1904)                                    c.                                                                              5-methyl-heptane-3,4-dione                                                                   n.c.; prepared by the                                                         method in Bull.[3], 31, 1145                                                  (1904); b.p. 55°C./12 mm.Hg.                   

The new compounds included in this group can be obtained as follows:

1. f. 5-Methyl-heptan-2,3-dione. 0.33 Mole of acetol, 0.33 mole ofα-methylbutanal and 2.5 2.5 of cone HCl were heated in a flask equippedwith a Raschig column (length 25 cm), and the volatile products weredistilled over as the reaction proceeded. 15 ml. of distillate werecollected and rejected. The flask was cooled, and 15 ml. of water wereadded to the distillation residue. The distillation was then continuedat a bath temperature of 150°-180° C. After 15 ml. of distillateconsisting of the reaction product and water had been collected, theflask was again cooled, and the addition of water followed bydistillation were repeated several times until the reaction product wascompletely distilled. The combined distillates were extracted with etherafter washing the extract with aqueous sodium carbonate and water andevaporation of the solvent, the residue was distilled. There wereobtained 3.9 g. of pure 5-methyl-heptan-2,3-dione distilling at 45°-47°C./8 Torr. n_(D) ²³.5 = 1.4200; d₄ ₂₃.5 = 0.9099.

1. g. 5-Methyl-octan-2,3-dione was prepared according to the same methodas 5-methyl-heptan-2,3-dione, except that 0.5 mole of acetol, 0.55 moleof a-methyl-pentenal and 4.5 ml. of conc. HC1 were used for thereaction. There were obtained 16 g. of pure 5-methyl-octan-2,3-dionedistilling at 65°-66° C./11 Torr; n_(D) ²².5 = 1.4258; d₄ ²².5 = 0.9107.

1. h. Acetylvalerianyl was prepared according to the same method ascompound (1) f. It has a b.p. of 71°14 72° C./44 mm.Hg.

1. i. Acetylheptanoyl was prepared by hydrolyzing 3-oximino-nonan-2-oneaccording to the method of Bouveault et al. described in Bull.Soc.Chim.France [3] 31, 1145 (1904). 3-Oximino-nonan-2one was obtained bynitrosation of nonan-2-one with ethyl nitrite according to the methoddescribed in Org. React. VII, Chap. 6 (1953), Acetylheptanoyl has a b.p.of 74° C./9 mm. Hg.

2. c. 5-Methyl-heptan-3,4dione was prepared according to the methoddescribed in Bull [3], 31, 1145 (1904). It has a b.p. of 55° C./12 mm.Hg.

The organoleptic evaluations are set out in Table XXIV below.

XXV -- Thiophene Alpha-diketones

Compounds of this group have the following general formula: ##SPC41##

wherein R₁ is hydrogen or a methyl group and wherein R₂ is an alkylgroup.

Representative compounds include:

    (1)  a.     1-(thienyl-2)-propane-1,2-dione                                                                         n.c.                                         b.     1-(3-methyl-thienyl-2)-propane-1,2-dione                                                                n.c.                                         c.     1-(5-methyl-thienyl-2)-propane-1,2-dione                                                                n.c.                                         d.     1-(thienyl-2)-butan-1,2-dione                                                                           n.c.                                

The new compounds included in this group can be obtained as follows:

1. a. 1-(Thienyl-2)-propane-1,2 dione was prepared by acylatingthiophene according to the method described in J.A.C.S. 72, 3695 (1950),subjecting the resulting 2-propionyl-thiophene to the action of nitrosylchloride and hydrolyzing the reaction product in formic acid solutionwith nitrosyl sulfuric acid as described in Bull. [3] 31, 1163 (1904).The product formed bright yellow crystals and melted at 48°-50° C.

1. b. 1-(3-methyl-thienyl-2)-propane-1,2 dione was prepared by acylatingthiophene according to the method described in J.A.C.S. 72, 3695 (1950),subjecting the resulting 3-methyl-2-propionyl-thiopene to the action ofnitrosyl chloride and hydrolizing the reaction product in formic acidsolution with nitrosyl sulfuric acid as described in Bull. [3] 31, 1163(1904). The product had a b.p. of 93° C./11 mm. Hg.

1. c. 1-(5-Methyl-thienyl-2)-propane-1,2-dione was prepared by the samemethod as compound (1) a. It has a b.p. of 150°-160° C. (bath temp.)/11mm. Hg.

1. d. 1-(Thienyl-2)-butan-1,2-dione was prepared from2-butyryl-thiophene via the oxime according to the method used in thefuran series and described in Tetrahedron 20, 2959 (1964). The producthas a b.p. of 120°-123° C. (bath temperature) 11 mm. Hg.

The organcleptic evaluations gave the results set out in TABLE XXVbelow.

XXVI -- Pyrrole Alpha-diketones

This group of compounds has the general formula: ##SPC42##

wherein R₁ is hydrogen or alkyl and R₂ is alkyl.

Representative compounds of this group include e.g.:

    (1)  a.     (pyrrolyl-2)-propan-1,2-dione                                                                         n.c.                                           b.     (pyrrolyl-2)-buten-1,2-dione                                                                          n.c.                                  

The new compounds included in this group can be obtained as follows:

1. a. (Pyrrolyl-2)-propan-1,2-dione was prepared according to the samemethod as used for compound (1) d. of Group XXV. It has a m.p. of 50°1451° C.

1. b. (Pyrrolyl-2)-butan-1,2-dione was prepared by the same method asused for compound (1) d. of Group XXV. It has a.m.p. of 37°-38° C.

Organoleptic evaluation data are set out in TABLE XXVI below.

XXVII -- Furan Esters

Compounds of this group have the general formulae: ##SPC43##

wherein R is an alkyl group comprising at least 2 carbon atoms;

and ##SPC44##

wherein R is an alkyl or alkenyl group.

Representative compounds of this group include:

    (1)                                                                              a.                                                                              furfuryl propionate                                                                            *"The Furans", page 226                                    b.                                                                              furfuryl butyrate                                                                              *"The Furans", page 226                                    c.                                                                              furfuryl isobutyrate                                                                           *"The Furans", page 226                                    d.                                                                              furfuryl isovalerate                                                                           n.c.                                                       e.                                                                              furfuryl crotonate                                                                             n.c.                                                       f.                                                                              furfuryl tiglate *"The Furans", page 36                                     g.                                                                              furfuryl alphamethylbutyrate                                                                   n.c.                                                       h.                                                                              furfuryl β, β'-dimethylacrylate                                                      n.c.                                                       i.                                                                              furfuryl valerate                                                                              n.c.                                                    (2)                                                                              a.                                                                              ethyl furoate    *"The Furans", page 513                                    b.                                                                              propyl furoate   *"The Furans", page 513                                    c.                                                                              isopropyl furoate                                                                              *"The Furans", page 513                                    d.                                                                              butyl furoate    *"The Furans", page 513                                    e.                                                                              isobutyl furoate *"The Furans", page 513                                    f.                                                                              isoamyl furoate  *"The Furans", page 513                                    g.                                                                              methyl 3-(α-furyl)-propionate                                                            C.A. 32, 53977 (1938)                                      h.                                                                              ethyl 3-(α-furyl)-propionate                                                             c.a.                                                     *"The Furans", Reinhold Publishing Company, New York (1953).             

The new compounds included in this group can be obtained by reacting thecorresponding acid chlorides with furfuryl alcohol, e.g. according tothe method described in Houben-Weyl, 4th ed., Vol. 8, 543 (1952). Thereare thus obtained:

1. d. Furfuryl isovalerate, b.p. 97°-98° C./11 mm. Hg.

1. e. Furfuryl crotonate, b.p. 96°-98° C./11 mm. Hg.

1. g. Furfuryl α-methybutyrate, b.p. 96° C./11 mm. Hg.

1. h. Furfuryl β ,β'-dimethylacrylate, b.p. 113°-115° C./ 11 mm. Hg.

1. i. Furfuryl valerate, b.p. 100°-104° C./11 mm. Hg.

In the organoleptic evaluation tests these compounds gave the resultsset out in TABLE XXVII below.

XXVIII -- Thiophene Esters

Compounds of this group have the following general formulae: ##SPC45##

wherein R is alkyl or furfuryl;

and ##SPC46##

wherein R is hydrogen or alkyl.

Representative compounds of this group include:

    (1)                                                                              a.                                                                              methyl thiophene-2-carboxylate                                                                 J.A.C.S. 77, 6709 (1955)                                   b.                                                                              ethyl thiophene-2-carboxylate                                                                  J.A.C.S. 77, 6709 (1955)                                   c.                                                                              propyl thiophene-2-carboxylate                                                                 J.A.C.S. 77, 6709 (1955)                                   d.                                                                              butyl thiophene-2-carboxylate                                                                  J.A.C.S. 77, 6709 (1955)                                   e.                                                                              isoamyl thiophene-2-carboxylate                                                                n.c.                                                       f.                                                                              furfuryl thiophene-2-carboxylate                                                               n.c.                                                    (2)                                                                              a.                                                                              thenyl formate   n.c.                                                       b.                                                                              thenyl acetate   n.c.                                                

The new compounds included in sub-class (1) of this group can beobtained by reacting thionyl chloride with the corresponding alkoxidesaccording to the method described in J.A.C.S. 77, 6709 (1955). Therewere thus obtained:

1. e. Isoamyl thiophene-2-carboxylate, b.p. 79°-80° C./ 0.3 mm. Hg.

1. f. Furfuryl thiophene-2-carboxylate, b.p. 109° C./ 0.07 mm. Hg.

The new compounds included in sub-class (2) of this group can beobtained by acylation of 2-thenyl alcohol which is prepared by reducingthiophene- 2-aldehyde according to the method described in J.Org.Chem.15, 790 (1950). Acylation with the mixed anhydride of formic and aceticacids according to the method described in J.A.S.C. 64, 1583 (1942)yields

2. a. Thenyl formate, b.p. 87°-88° C./15 mm. Hg.

Acylation with acetic anhydride yields

2. b. Thenyl acetate, b.p. 91° C./12 mm. Hg.

In the organoleptic evaluation test these compounds gave the results setout in TABLE XXVIII below.

XXIX -- Pyridine Esters

Compounds of this group are of the general formula ##SPC47##

wherein R stands for lower alkyl and n is 0 or 1.

Representative compounds of this group include:

    (1) a.   methyl (pyridyl-2)-acetate                                                                      c.a.                                               b.       methyl (pyridyl-3)-acetate                                                                      c.a.                                               c.       methyl (pyridyl-4)-acetate                                                                      c.a.                                               d.       ethyl (pyridyl-2)-acetate                                                                       c.a.                                               (1) e.   ethyl (pyridyl-3)-acetate                                                                       c.a.                                               f.       ethyl (pyridyl-4)-acetate                                                                       c.a.                                           

Organoleptic evaluation data are set out in TABLE XXIX below.

XXX -- Aromatic Sulfur Compounds

Compounds of this group are of the general formulae: ##SPC48##

wherein R₁ stands for hydrogen, hydroxy, alkoxy or alkyl and R₂represents hydrogen or alkyl; ##SPC49##

wherein R₁ stands for hydrogen, hydroxy, alkyl or alkoxy, R₂ may behydrogen or alkyl, R₃ represents alkyl or benzyl and n is 0, 1 or 2; and##SPC50##

wherein R stands for alkyl or phenyl.

Representative compounds include:

    (1) a.                                                                              2-methoxy benzenethiol                                                                         Ber. 39, 1348 (1906)                                   b.    benzenethiol     c.a.                                                   c.    2-hydroxy-thiophenol                                                                           Beilatein 6, 793                                       d.    2-methyl-benzenethiol                                                                          c.a.                                                   e.    3-methyl-benzenethiol                                                                          c.a.                                                   f.    4-methyl-benzenethiol                                                                          c.a.                                                   g.    2,4-dimethyl-benzenethiol                                                                      Ber. 32, 1147                                          h.    3,4-dimethyl-benzenethiol                                                                      J.Org.Chem.26, 4047 (1961)                             i.    2-ethyl-benzenethiol                                                                           Ber. 59, 349                                           j.    2-ethoxy-benzenethiol                                                                          J.pr.Ch. 114, 231, 235                                 k.    4-methoxy-benzenethiol                                                                         c.a.                                                   (2) a.                                                                              methyl phenyl sulfide                                                                          c.a.                                                   b.    dibenzyl sulfide J.Chem.Soc. 1922, 1404                                 (3) a.                                                                              phenyl methyl disulfide                                                                        J.A.C.S. 85, 1618 (1963)                               b.    diphenyl disulfide                                                                             Ber. 56, 1929 (1923)                               

Evaluation test data are set out in TABLE XXX below.

XXXI -- Furan Sulfur Compounds

Compounds of this group are included in the formulae: ##SPC51##

wherein R may be hydrogen, alkyl or alkenyl and n stands for 1 or 2;##SPC52##

wherein R₁ stands for hydrogen or alkyl, R₂ represents hydrogen, alkyl,furfuryl or alkyl-substituted phenyl, and n stands for 0, 1 or 2, withthe provision that, if R₁ is hydrogen and n is 1, R₂ is neither methylnor furfuryl; ##SPC53##

wherein R is alkyl or furfuryl; ##SPC54##

wherein R₁ represents hydrogen or alkyl and R₂ stands for alkyl orfurfuryl; and ##SPC55##

wherein R represents an alkyl or an acyl group.

Representative compounds in this group include:

    (1) a.                                                                            furfurylthiol acetate                                                                             n.c.                                                  b.  furfurylthiol propionate                                                                          n.c.                                                  c.  furfurylthiol butyrate                                                                            n.c.                                                  d.  furfurylthiol furoate                                                                             n.c.                                                  e.  furfurylthiol β,β-dimethylacrylate                                                      n.c.                                                  f.  furfurylthiol tiglate                                                                             n.c.                                                  g.  furfurylthiol formate                                                                             n.c.                                                  h.  2-(furyl-2)-ethanthiol acetate                                                                    n.c.                                                  (2) a.                                                                            5-methylfurfuryl methyl sulfide                                                                   n.c.                                                  b.  furfuryl propyl sulfide                                                                           n.c.                                                  c.  furfuryl isopropyl sulfide                                                                        n.c.                                                  d.  furfuryl 5-methylfuryl sulfide                                                                    n.c.                                                  e.  5-methylfuryl methyl sulfide                                                                      n.c.                                                  f.  2-(furyl)-2)-ethanthiol                                                                           n.c.                                                  (3) a.                                                                            methylthiol furoate n.c.                                                  (4) a.                                                                            difurfuryl disulfide                                                                              J.A.C.S. 52, 2141 (1930)                              (5) a.                                                                            (benzofuryl-2)-methyl methyl sulfide                                                              n.c.                                                  b.  (benzofuryl-2)-methylthiol acetate                                                                n.c.                                              

The new compounds included in this group XXXI can be obtained asfollows:

1. a. Furfurylthiol acetate was prepared by reacting acetic chloride oranhydride with furfurylmercaptan according to the method described inHouben-Weyl, 4l th ed., vol. 9, 753 (1955). The product has a b.p. of90°-92° C./12 mm. Hg.

According to the same method, but starting from the corresponding acidchloride or anhydride, the following products were obtained: 4

1. b. Furfurylthiol propionate, b.p. 95°-97° C./10 mm. Hg.

1. c. Furfurylthiol butyrate, b.p. 105.5°-106.5° / 10 mm. Hg.

1. d. Furfurylthiol furoate, b.p. 110° C./0.01 mm. Hg.

1. e. Furfurylthiol β,β-dimethylacrylate, b.p. 85° C./ 0.015 mm. Hg.

1. f. Furfurylthiol tiglate, b.p. 84.5°-87.5° C./ 0.03 mm. Hg.

1. g. Furfurylthiol formate was prepared according to the method usedfor the synthesis of furfuryl formate and described in J.A.C.S. 64, 1583(1942). The product had a b.p. of 77°-78° C./ 8 mm. Hg.

1. h. 2-(Furyl- 2 )-ethanthiol acetate was prepared by reactingthioacetic acid with 2-vinyl-furance under the action of UV light and inthe presence of benzoyl peroxide according to the method described inJ.Org.Chem. 27, 2853 (1962). The thio-ester, after isolation bydistillation had a b.p. of 100°-103° C./ 0.05 mm. Hg.

2. a. 5 -Methylfurfuryl methyl sulfide was prepared by reacting5-methylfurfuryl-mercaptan with dimethyl sulfate in alkaline solutionaccording to known methods. 5-Methylfurfuryl-mercaptan was obtained fromthe corresponding alcohol by the method described in Org.Syn. 35, 67(1955). The product is a colorless liquid boiling at 71°-72° C./11 mm.Hg.

2. b. Furfuryl propyl sulfide was prepared by reacting sodiumfurfurylmercaptide with n-propyl bromide according to the methoddescribed in Houben-Weyl, 4th ed., vol. 9, 97 (1955). The product has ab.p. of 91° C./15 mm. Hg.

2. c. Furfuryl isopropyl sulfide was prepared by the same method as usedfor compound (2) b., except that isopropyl bromide was used instead ofn-propyl bromide. The product has a b.p. of 84° C./16 mm. Hg.

2. d. Furfuryl 5 -methylfurfyl sulfide was prepared according to themethod used for the synthesis of alkylthio-furans and described in C.A.59, 8681d (1963). 2-Methylfuran was reacted with butyl-lithium and thenwith sulfur. The resulting thiol was further reacted (without priorisolation) with furfuryl chloride. The product was a slightly yellowishoil having a b.p. of 67° C./ 0.04-0.05 mm. Hg.

2. e. Methyl 5 -methylfuryl sulfide was prepared by the same method asused for compound (2) d. The product was a light yellow liquid having ab.p. of 80° C./45-50 mm. Hg.

2. f. 2 -(Furyl- 2 )-ethanethiol was prepared by saponifying 24 g. of2-furylethanethiol acetate with alkali in aqueous-alcoholic medium.After refluxing for 90 minutes the reaction mixture was neutralized withacetic acid and then extracted with ether. Upon distillation there wereobtained 14.4 g. of 2-(furyl-2)-ethanethiol having a b.p. of 61°-62°C./0.03 mm. Hg; n_(D) ²².3 = 1.5653; d₄ ²³.2 = 1.153

3. a. Methylthio fuorate was prepared by reacting furoyl chloride withmethylmercaptan according to the method described in Houben-Weyl, 4thed., vol. 9, 753 (1955). It has a b.p. of 92°-93° C./11 mm. Hg.

5. a. Benzofurfuryl- 2 methyl sulfide was prepared by reacting(benzofurfuryl-2)-mercaptan with dimethyl sulfate in alkaline solution.The sulfide thus obtained has a b.p. of 108°-109° C./0.4 mm. Hg.

The starting (benzofurfuryl-2)-mercaptan was obtained from thecorresponding alcohol according to the method described in Org. Synth.35, 67 (1955).

5. b. (Benzofurfuryl- 2 )-thiol acetate was prepared by the same methodas used for compound (1) a. (furfurylthiol acetate). The product has ab.p. of 120°-122° C./0.8 mm. Hg.

Evaluation test data are set out in TABLE XXXI below.

XXXII -- Thiophene Sulfur Compounds

This group comprises compounds corresponding to the following generalformulae: ##SPC56##

wherein R represents hydrogen, alkyl, acetyl or thenyl, and n is 1 or 2;

and ##SPC57##

wherein R stands for alkyl or furfuryl.

Specific examples of compounds corresponding to these formulaeinclude:(1) a. thenyl-mercaptan Compt.rend. 229, 1343 (1949) b. thenylmethyl sulfide Compt.rend. 229, 1343 (1949) c. thenylthiol acetate n.c.d. 2-(thienyl-2)-ethanethiol n.c. e. 2-(thienyl-2)-ethanethiol acetaten.c. f. dithenyl sulfide n.c.(2) a. thiothenoic acid S-methyl ester n.c.b. thiothenoic acid S-ethyl ester n.c. c. thiothenoic acid S-furfurylester n.c.

The new compounds of this group can be obtained as follows:

1. c. Thenylthiol acetate was prepared by the same method as used forcompound (1) a. (furfurylthiol acetate) of Group XXXI above. The productis a colorless liquid having a b.p. of 113°-114° C.

1. d. 2 -Thienyl- 2 )-ethanethiol). 2-Vinyl-thiophene [obtained by themethod described in Org. Synth. 38, 86 (1958)] was reacted withthioacetic acid according to the method described in J.Org.Chem. 27,2853 (1962), and the resulting addition product was subjected tohydrolysis with an acid. The product has a b.p. of 55° C./0.1 mm. Hg.

1. e. 2 -(Thienyl- 2 )-ethanethiol acetate was obtained as theintermediate product obtained by reacting 2-vinyl-thiophene withthioacetic acid in the preparation of compound (1) d. above. The producthas a b.p. of 90° C./0.07 mm. Hg.

1. f. Dithenyl sulfide was prepared by the same method as used forcompound (1) b. (dithenyl ether) of Group X above, except thatthenylmercaptan was used instead of thenyl alcohol. The product has ab.p. of 118° C./0.04 mm. Hg.

Compounds (2) a, (2) b. and (2) c. were prepared by reacting thionylchloride with the sodium salts of the corresponding mercaptans inalcoholic solution according to the method described in J.C.A.S. 77,6709 (1955). After refluxing for 1 hour the reaction mixture wasfiltered and concentrated. The residue was purified by chromatography ona silica-gel column using a benzene-hexane mixture 8:2 as the eluant.The structure of the resulting products was identified by massspectrometry:

2. a. Thiothenoic acid S-methyl ester: Ion peaks with relativeintensities: 111 (100%), 39 (22%) and 158 (12%).

2. b. Thiothenoic acid S- ethyl ester: Ion peaks with relativeintensities: 111 (100%), 39 (17%) and 172 (10%).

2. c. Thiothenoic acid S- furfuryl ester: Ion peaks with relativeintensities: 111 (100%), 81 (73.5%) and 39 (20%).

Organoleptic evaluation data are set out in TABLE XXXII below.

XXXIII -- Pyridine Sulfur Compounds

The compounds included in this group have the general formula: ##SPC58##

wherein R stands for hydrogen, alkyl, acyl or pyridyl, and n is 0 or 1.

As examples there can be mentioned:

    __________________________________________________________________________    As examples there can be mentioned:                                           (1)                                                                              a.                                                                              (pyridyl-2)-methanthiol                                                                           C.A. 55, 4542b (1961)                                   b.                                                                              2-mercapto-pyridine c.a.                                                    c.                                                                              2-methylthio-pyridine                                                                             n.c.                                                    d.                                                                              2-ethylthio-pyridine                                                                              n.c.                                                    e.                                                                              (pyridyl-2)-thiol acetate                                                                         n.c.                                                    f.                                                                              di(pyridyl-2)-sulfide                                                                             J.Chem.Soc. 1942, 239                                   g.                                                                              2-(pyridyl-2)-ethanethiol                                                                         J.Org.Chem. 26, 82 (1961)                               h.                                                                              2-(pyridyl-2)-ethyl methyl sulfide                                                                see below                                               i.                                                                              2-(pyridyl-2)-ethyl ethyl sulfide                                                                 n.c.                                                    j.                                                                              2-(pyridyl-2)-ethanethiol acetate                                                                 see below                                               k 2-(pyridyl-2)-ethyl furfuryl sulfide                                                              n.c.                                                    l.                                                                              (pyridyl-2)-methyl methyl sulfide                                                                 Helv. 47, 1754 (1964)                                   m.                                                                              (pyridyl-2)-methyl ethyl sulfide                                                                  n.c.                                                    n.                                                                              (pyridyl-2)-methanethiol acetate                                                                  n.c.                                                 __________________________________________________________________________

The method used for preparing the known compound (1) h.[2-(pyridyl-2)-ethyl methyl sulfide] was as follows: 2-Vinylpyridine wasreacted with methylmercaptan by the action of UV light in the presenceof trace amounts of benzoyl peroxide and disphenyl sulfide. The producthas a b.p. of 48° C./0.03 mm. Hg.

The same method was used for preparing the known compound (1) j., exceptthat thioacetic acid was used instead of methylmercaptan. The producthas a b.p. of 80° C./0.02 mm. Hg.

The new compounds included in this Group XXXIII can be obtained asfollows:

1. c. 2 -Methylthio-pyridine was prepared according to the methoddescribed in Houben -Weyl, 4th ed., vol. 9, 7 (1955) by alkylating2-mercapto-pyridine with methyl halide. The resulting pryridinium saltwas neutralized with NaOH and the base thus obtained extracted anddistilled. The product had a b.p. of 67°-68° C./10 mm. Hg.

1. d. 2 -Ethylthio-pyridine was prepared by the same method as used forcompound (1) c., except that ethyl halide was used instead of methylhalide. The product had a b.p. of 77°-77.5° C./ 8 mm. Hg.

1. e. Pyridyl- 2 )-thiol acetate was prepared by reacting aceticanhydride with 2-mercaptopyridine in alkaline medium according to themethod described in Houben-Weyl, 4th ed., vol. 9, 753 (1955) and inJ.A.C.S. 59, 1089 (1937). The product has a b.p. of 117°-118° C./9 mm.Hg.

1. i. 2 (Pyridyl- 2 )-ethyl ethyl sulfide was prepared by the samemethod as used for compound (1) h., except that ethylmercaptan was usedinstead of methylmercaptan. The product has a b.p. of 62° C./0.005 mm.Hg.

1. m. (Pyridyl- 2 )-methyl ethyl sulfide was prepared by the same methodas used for compound (1) 1. The product has a b.p. of 107°-110° C./10mm. Hg.

1. n. (Pyridyl- 2)-methanethiol acetate was prepared by reacting acetylchloride with 2-mercaptomethylpyridine in alkaline medium. Te producthas a b.p. of 102°-103° C./9 mm. Hg.

Evaluation test data are reported in TABLE XXXIII below.

XXXIV -- Pyrrole Sulfur Compounds

These sulfur compounds correspond to the following general formula:##SPC59##

wherein R represents alkyl, furfuryl, or aoyl. As examples, there can bementioned:(1) a. N-methyl-pyrryl-2 methyl sulfide n.c. b.N-methyl-pyrryl-2 ethyl sulfide n.c. c. N-methyl-pyrryl-2 furfurylsulfide n.c. d. (N-methyl-pyrryl-2)-methylthiol acetate n.c.

The new compounds included in this Group XXXIV can be obtained asfollows:

1. a. N-Methyl-pyrryl- 2 methyl sulfide was prepared by alkylating ofN-methyl-(pyrryl-2)-methylmercaptan with methyl iodide according to themethod described in Houben-Weyl, 4th ed., vol. 9, 97 (1955). The producthas a b.p. of 90° C./10 mm. Hg.

1. b. N-Methyl-pyrryl- 2 ethyl sulfide was prepared by the same methodas used for compound (1) a., except that ethyl bromide was used in placeof methyl iodide. The product has a b.p. of 99° C./10 mm. Hg.

1. c. N-Methyl-pyrryl-2 furfuryl sulfide was prepared by the same methodas used for compound (1) a., except that furfuryl chloride was used inplace of methyl iodide. The product has a b.p. of 94° C.//0.01 mm. Hg.

1. d. (N-Methyl-pyrryl- 2 )-methylthiol acetate was prepared byacylating (N-methyl-pyrryl-2)-methylmercaptan according to the methoddescribed in Houben-Weyl, 4th ed., vol. 9, 753 (1958). The product has ab.p. of 69° C./0.05 mm. Hg.

Evaluation test data are set out in TABLE XXXIV below.

XXXV -- Pyrazine Sulfur Compounds

The compounds of this group can be represented by the following generalformulae: ##SPC60##

wherein n is 0, 1 or 2, R₁ represents hydrogen, alkyl, acyl or furfuryland R₂ stands for hydrogen or methyl with the proviso that R₁ and R₂cannot both be methyl if n is 0; ##SPC61##

wherein R stands for hydrogen, alkyl, furfuryl or acyl.

Illustrative examples of compounds corresponding to formulae (1) and (2)include:

    (1)                                                                              a.                                                                              (2-methylpyrazinyl-3, -5 and -6) furfuryl sulfide                                                        n.c.                                             b.                                                                              pyrazinylmethyl-mercaptan  n.c.                                             c.                                                                              pyrazinylmethyl methyl sulfide                                                                           n.c.                                             d.                                                                              pyrazinylmethyl ethyl sulfide                                                                            n.c.                                             e.                                                                              pyrazinylmethyl furfuryl sulfide                                                                         n.c.                                             f.                                                                              pyrazinylmethylthiol acetate                                                                             n.c.                                             g.                                                                              2-pyrazinyl-ethyl mercaptan                                                                              n.c.                                             h.                                                                              2-pyrazinyl-ethyl methyl sulfide                                                                         n.c.                                             i.                                                                              2-pyrazinyl-ethyl ethyl sulfide                                                                          n.c.                                             j.                                                                              2-pyrazinyl-ethyl furfuryl sulfide                                                                       n.c.                                             k.                                                                              2-pyrazinyl-ethylthiol acetate                                                                           n.c.                                          (2)                                                                              a.                                                                              2,5-dimethyl-3-mecapto-pyrazine                                                                          n.c.                                             b.                                                                              2,5-dimethyl-3-methylthio-pyrazine                                                                       n.c.                                             c.                                                                              2,5-dimethyl-3-ethylthio-pyrazine                                                                        n.c.                                             e.                                                                              2,5-dimethyl-3-acetylthio-pyrazine                                                                       n.c.                                             d.                                                                              2,5-dimethyl-3-furfurylthio-pyrazine                                                                     n.c.                                      

The new compounds included in this group can be obtained as follows:

1. a. (2 -Methylpyrazinyl- 3, -5 and -6) furfuryl sulfide (mixture): Amixture of 2-methyl-3-, 5- and 6-chloropyrazine was prepared bychlorination of 2-methylpyrazine according to the method described inJ.Org.Chem. 26, 2356, 2360 (1961). 0.2 Mole of the above2-methyl-chloropyrazine mixture was added to 0.2 mole of a sodiumfurfurylmercaptide suspension in 250 ml. of xylene. The mixture wasboiled for 6 hours. After cooling 250 ml. of water were added, theorganic layer was concentrated and distilled. 13.5 g. of a mixture of(2-methylpyrazinyl-3, -5 and -6) furfuryl sulfide were obtained; b.p.153°-156° C./10 Torr; n_(D) ²⁰ = 1.5970; d₄ ²⁰ = 1.2164.

1. b. Pyrazinylmethylmercaptan: a solution of 6.3 g. (0.05 mole) ofchloromethylpyrazine [obtained according to the method described inJ.Org.Chem. 26, 2356 (1961)] in 20 ml. of ether was added slowly, withstirring, to a solution of sodium hydrogensulfide (60%) in 50 ml. ofabsolute methanol. Stirring of the reaction mixture at room temperaturewas continued for 3 hours. The precipitate which had formed was removedby filtering, the solvents were evaporated, and the residue wasdissolved in water. The solution was extracted twice with ether. Theaqueous phase was neutralized with acetic acid and extracted with ether.After drying of the extract the solvent was evaporated and the residuedistilled. 0.25 g. of pyrazinylmethylmercaptan boiling at 44°-45°C./0.07 mm. Hg. was obtained.

1. c. Pyrazinylmethyl methyl sulfide was prepared according to themethod described in Houben-Weyl, 4th ed., vol. 9, 97 (1955) by reactingchloromethylpyrazine [obtained by the method described in J.Org.Chem.26, 2356 (1961)] with sodium methylmercaptide. The product has a b.p. of105°-106° C./12 mm. Hg.

1. d. Pyrazinylmethyl ethyl sulfide was prepared by the same method asused for compound (1) c., except that sodium ethylmercaptide was used inplace of sodium methylmercaptide. The product has a b.p. of 114°-116°C./12 mm. Hg.

1. e. Pyrazinylmethyl furfuryl sulfide was prepared by the same methodas used for compound (1) c., except that sodium furfurylmercaptide wasused instead of sodium methylmercaptide. The product has a b.p. of 116°C./0.05 mm. Hg.

1. f. Pyrazinylmethylthiol acetate was prepared by acetylation ofpyrazinylmethylthiol according to the method described in Houben-Weyl,4th. ed., vol. 9, 753 (1955). The product has a b.p. of 52° C./0.02 mm.Hg.

1. g. 2 -Pyrazinyl-ethyl mercaptan was prepared by reactingvinylpyrazine [obtained by the method described in J.Org.Chem. 27, 1363(1962)] and hydrolizing the resulting thiolic acid ester according tothe method described in J.Org.Chem. 22, 980 (1957). The product has ab.p. of 56.5°-60° C./0.003 mm. Hg.

1. h. 2 -Pyrazinyl-ethyl methyl sulfide was prepared by reactingvinylpyrazine [c.f. J.Org.Chem. 27, 1363 (1962)] with methylmercaptan bythe action of ultra violet light and in the presence of benzoyl peroxideby the method described in Acta Chem. Scand. 8, 295 (1954). The productwas identified by mass apectrometry. It has a b.p. of 57°-69° C. at 0.05mm. Hg.

1. i. 2 -Pyrazinyl-ethyl ethyl sulfide was prepared by the method usedfor compound (1) h., but using ethylmercaptan. It has a b.p. of 75°C./0.03 mm. Hg.

1. j. 2 -Pyrazinyl-ethyl furfuryl sulfide was prepared by the methodused for compound (1) h., but using furfuralmercaptan. The product has ab.p. of 116°-117° C./0.01 mm. Hg.

1. k. 2 -Pyrazinyl-ethylthiol ethylthiol acetate was prepared byreacting vinylpyrazine with thioacetic acid in the presence of benzoylperoxide as a catalyst according to the method described in J.Org.Chem.27, 2853 (1962). The product has a b.p. or 80° C./0.02 mm. Hg.

2. a. 2,3 -Dimethyl- 3 -mercapto-pyrazine: A solution of 1.3 g. (0.023mole) of sodium hydrogensulfide and 2.5 g. (0.01 mole) of1,5-dimethyl-3-iodo-pyrazine in 70 ml. of absolute methanol was refluxedfor 3 hours. After evaporation of the alcohol the residue was dissolvedin 1-n NaOH, the solution was filtered and the filtrate was neutralizedwith acetic acid. After isolation by the usual treatments the reactionproduct was sublimated. There was obtained 0.81 g. of a yellow powderhaving a m.p. of 182°-185° C.

2. b. 2,5 -Dimethyl- 3 -methylthio-pyrazine: 2.85 g. (0.02 mole) of2,5-dimethyl-3-chloropyrazine and 0.06 mole of methylmercaptan weredissolved in a solution of 0.7 g. of sodium in 20 ml. of absoluteethanol. The reaction mixture was refluxed for 45 minutes. After removalof the alcohol by distillation the residue was dissolved in water andthe sulfide was extracted with ether and distilled. The product (yield75.6%) has a b.p. of 40°-50° C./11 mm. Hg.

2. c. 2,5 -Dimethyl- 3 -ethylthio-pyrazine was prepared in the samemanner as compound (2) b., except that 0.06 mole of ethylmercaptan wasused instead of methylmercaptan. The product (yield 75%) has a b.p. of128° C./9 mm. Hg.

2. d. 2,5 -Dimethyl- 3furfurylthio-pyrazine was prepared in the samemanner as compound (2) b., except that 0.06 mole of furfurylmercaptanwas used instead of methylmercaptan. The product (yield 75%) has a b.p.of 115°-120° C./0.02 mm. Hg.

2. e. 2,5 -Dimethyl- 3 acetylthio-pyrazine was prepared by acetylating2,5-dimethyl-3-mercapto-pyrazine [compound (2) a. ] with aceticanhydride in an alkaline medium according to the method described inHouben-Weyl, 4th ed., vol. 9, 753 (1955). The product has a m.p. of36°-42° C.

Oganoleptic evaluation test data are reported in TABLE XXXV below.

XXXVI -- Phenols and Phenol Ethers

The compounds of this group can be represented by the following generalformulae: ##SPC62##

wherein R₁ represents alkyl or acetyl and R₂ represents hydrogen ormethyl, with the proviso that R₁ and R₂ together comprise at least 2carbon atoms; ##SPC63##

wherein R represents alkyl.

Examples of compounds defined by the above formulae: (1), (2) and (3)include:

    (1) a.                                                                            2-ethyl-phenol    c.a.                                                    b.  3-ethyl-phenol    c.a.                                                    (1) c.                                                                            4-ethyl-phenol    c.a.                                                    d.  4-isopropyl-phenol                                                                              Compt.rend. 177, 453                                                          (1923)                                                  e.  2,3-xylenol       c.a.                                                    f.  2,4-xylenol       c.a.                                                    g.  2,5-xylenol       c.a.                                                    h.  2,6-xylenol       c.a.                                                    i.  3,4-xylenol       c.a.                                                    j.  3,5-xylenol       c.a.                                                    k.  2-hydroxy-acetophenone                                                                          c.a.                                                    l.  2-hydroxy-propiophenone                                                                         Org.Synth.13, 90 (1933)                                 m.  4-hydroxy-propiophenone                                                                         Org.Synth.13, 90 (1933)                                 n.  5-methyl-2-hydroxy-acetophenone                                                                 Ann. 460, 83 (1927)                                     (2) a.                                                                            2,3,5-trimethyl-phenol                                                                          c.a.                                                    b.  2,4,6-trimethyl-phenol                                                                          c.a.                                                    c.  2,4,5-trimethyl-phenol                                                                          c.a.                                                    d.  3,4,5-trimethyl-phenol                                                                          c.a.                                                    (3) a.                                                                            4-ethyl-2-methoxy-phenol                                                                        c.a.                                                    b.  4-propyl-2-methoxy-phenol                                                                       Helv. 8, 334 (1925)                                         The present group also comprises the single compound                      (4) a.                                                                            4-vinyl-1,2-dimethoxy-benzene.                                        

Evaluation test data are set out in TABLE XXXVI below.

XXXVII -- Aliphatic Oxoalcohols

This group comprises compounds having the general formula

    R-CO-CH.sub.2 OH                                           1

wherein R stands for alkyl. Examples of compounds corresponding to thisdefinition include:

    (1) a.                                                                              2-Oxo-propan-1-ol                                                                            Ann. 596, 61 (1955)                                      (1) b.                                                                              2-oxo-butan-1-ol                                                                             Ann. 596, 68 (1955)                                  

Flavor evaluation data are set out in TABLE XXXVII below.

XXXVIII -- Miscellaneous

This group comprises compounds of the classes represented by thefollowing general formulae: ##SPC64##

wherein R stands for hydrogen, methyl or ethyl; ##SPC65##

wherein each of the symbols X and Y represents oxygen or sulfur;

    R.sub.1 --CH.sub.2 COCHJ.sub.2 S--R.sub.2                  3

wherein R₁ represents hydrogen or alkyl and R₂ stands for alkyl orfurfuryl;

and ##EQU2## wherein R₁ is alkyl and R₂ stands for alkyl or furfuryl.

Specific compounds included in the above formulae are:

    (1) a.                                                                            thiophane-3-one   J.A.C.S. 68, 2229 (1946)                                b.  2-methyl-thiophane-3-one                                                                        Helv. 27, 124 (1944)                                    (2) a.                                                                            2,6-dimethyl-gamma-pyrone                                                                       Ber. 69, 2379 (1936)                                    b.  2,6-dimethyl-thio-gamma-pyrone                                                                  Ber. 52, 1539 (1919)                                    c.  2,6-dimethyl-dithio-gamma-pyrone                                                                Compt.rend. 238, 1717 (1954)                            (3) a.                                                                            furfurylthioacetone                                                                             n.c.                                                    b.  1-methylthio-butan-2-one                                                                        n.c.                                                    c.  methylthioacetone J.A.C.S. 76, 164 (1954)                                 (4) a.                                                                            dimethylmercaptal of                                                          α-methylbutanal                                                                           n.c.                                                    b.  difurfurylmercaptal of                                                        α-methylbutanal                                                                           n.c.                                                        The present group also includes: -(5) a.                                                        5-methyl-furyl-2-nitrile                                                                     J.A.C.S. 54, 2549 (1932)             

The new compounds included in this group XXXVIII can be obtained asfollows:

3. a. Furfurylthioacetone was prepared in the same manner asmethylthioacetone [cf. compound (3)c.] according to the method describedin J.A.C.S. 76, 114 (1954) by condensing 0.122 mole of chloroacetonewith 0.11 mole of sodium furfurylmercaptide. After the usual separationand purification of the reaction product there were obtained bydistillation 13.9 g. of pure furfurylthioacetone distilling at 115-177°C./10 Torr. n_(D) ²².8 = 1.5250; d₄ ²³ = 1.150.

3. b. 1-Methylthio-butan-2-one was prepared in the same manner asmethylthioacetone according to the method described in J.A.C.S. 76, 114(1954) by condensing 0.122 mole of 1-chlorobutan-2-one [obtainedaccording to the method described in Ber. 82, 229 (1949)] with 0.11 moleof sodium methylmercaptide. The reaction produce was separated byfiltration from the NaCl formed in the reaction and concentration of thefiltrate. By distillation of the residue there were obtained 8.2 g. ofpure 1-methylthiobutan-2-one distilling at 52°-53° C./8 Torr. n_(D) ²² =1.4700; d₄ ²² = 0.9970.

4. a. Dimethylmercaptal of α -methylbutanal: Dry HCl was introduced intoa mixture of 0.05 mole α-methylbutanal and 0.11 mole methanthiol. Bycooling the temperature was maintained between 0° and 5° C. After 15minutes 50 ml. of water were added, the mixture extracted with ether,the ether layer washed with a NaHCO₃ solution and water. By distillationof the ether concentrate 4.2 g. of dimethylmercaptal of α-methylbutanolwere obtained; b.p. 75°-76° C./8 Torr; n_(D) ²⁴ = 1.5050; d₄ ²⁴ =0.9761.

4. b. Difurfurylmercaptal of α -methylbutanol: This compound wasprepared by the same method as compound (4) a., using 0.11 mole offurfurylmercaptan instead of methanthiol. 6.4 g. of difurfurylmercaptalwere obtained; b.p. 130° C./0.1 Torr; n_(D) ²².8 = 1.5500; d₄ ²³ =1.126.

Organoleptic evaluation as flavor agents gave the results set out inTABLE XXXVIII below.

ORGANOLEPTIC EVALUATIONS

As was described above, the compounds of this invention were subjectedto organoleptic evaluation tests either in a syrup base (A), or one ofthe two soluble coffee bases (B and C). The following tables give theresults of these organoleptic evaluations. In the tables, the Romannumeral refers to the number of the group from which the test compoundswere selected. The column headed "Number" refers to the number of thetest compound of the corresponding group. The column head "Test" givesthe Method of the Test, as described hereinbefore, and the column headed"Quantity" sets out the amount of the Test Compound used in grams per100 liters of the base material.

                  ORGANOLEPTIC EVALUATION TABLES                                  ______________________________________                                        Number                                                                              Test   Quantity  Organoleptic Characterization                          ______________________________________                                        TABLE I                                                                       (1)a. A      0.2       neroli-, bergamot- and                                                        cinnamon-like; natural note                            (1)b. A      0.05      green note                                             (1)c. A      0.15      green note; rose-like                                  (1)d. A      1         grape- and fig-like                                    (1)d. C      0.03      winey, buttery, woody, nutty                           (1)e. A      5         green, metallic taste                                  TABLE II                                                                      (1)a. A      0.05 to   green, musty taste                                                  0.1                                                              (1)b. A      0.1       oily, aromatic                                         (1)c. A      0.15      oily taste                                             (1)d. A      0.15      aromatic taste                                         (1)e. A      1.0       aromatic taste                                         (1)f. A      0.25      mouldy, tarry taste                                    (1)g. A      1.0       mouldy, aromatic taste                                 (1)h  A      0.25      aromatic taste                                         (1)i. A      1.0       earthy taste                                           (1)j. A      2.0       sweet, anise- and honey-like taste                     (1)k. A      0.5       strawberry-like                                        (1)l. A      0.25      earthy taste                                           (1)m. A      1         slightly fruity; dry                                   (1)n. A      0.15      fatty, earthy taste                                    (1)o. A      0.25-0.50 aromatic taste                                         (1)p. A      1.0       aromatic earthy taste                                  TABLE III                                                                     (1)a. A      0.5       phenolic; coffee-grounds                               (1)a. B      0.5-1.0   enhancement of the roasted note                        (1)a. C      0.68      groundsy; cereal-like                                  (2)a. A      0.05      styrene-like; aromatic                                 (2)b. A      1-3       slightly phenolic; burnt taste                         (2)b. B      0.4       enhancement of the bitter note                         (2)c. A      0.3       salicylate-like taste                                  (2)d. A      0.25      earthy flavor note                                     (2)e. A      1.0       burnt, caramel taste                                   (2)f. A      0.25      phenolic; saffron-like                                 (2)g. B      0.12      earthy; mushroom-like; hazelnut                        (2)h. B      0.50      burnt; green-taste                                     (2)i. B      0.095     earthy flavor note                                     (3)a. A      1.0       aromatic taste                                         (3)a. C      0.1       medicinal; camphor; ricy                               (3)b. A      1.0       green-cooked taste                                     (3)a. C      0.11      liquorice-like; sen-sen                                (3)c. A      2.0       green-owdery taste                                     (3)c. C      0.068     bitter; wintergreen mouthfeel                          TABLE IV                                                                      (1)a. B      0.75      roasted; bitter; green                                 (1)a. C      1.1       nitrobenzene-like                                      (1)b. B      0.85      fatty; winey                                           (1)c. A      1.0       styrene-like                                           (1)d. A      0.5       styrene-like                                           (1)e. A      1.0       chemical-like taste                                    (1)f. A      0.1       styrene-like                                           (1)g. C      0.11      hydrocarbon like                                       (1)h. A      0.1       burnt; horn-like; methyl furoate-like                  (1)h. C      0.54      solvent; latex paint-like                              (1)i. A      1.0       diphenyloxide-like                                     (1)j. A      1.0-2.0   onion-like                                             (1)k. A      1.0       green taste                                            (2)a. A      0.05      styrene-like                                           (2)a. C      0.01      sulfury; nutty; buckwheat-like                         (3)a. A      0.25      fruity, green                                          (3)a. C      0.01      geranium,metallic; acid; sulfury                       (3)b. A      1.0       fruity taste                                           (3)c. A      0.5       green taste                                            (3)c. C      0.068     apricot,medicinal; sulfury; sour                       (3)d. A      1.0       dry fruit flavor                                       (4)a. A      0.025     dry phenolic taste                                     (4)a. B      0.042     modified phenolic note                                 (4)a. C      0.042     iodoform; sulfury                                      (4)b. A      1.0       fruity; green taste                                    (5)a. B      0.006     hydrocarbon; rubbery; earthy                           (5)b. B      0.12      hydrocarbon; phenolic                                  TABLE V                                                                       (1)a. A      0.2       burnt taste                                            (1)b. A      0.1       green, fatty taste                                     (1)c. A      0.03      fatty taste                                            (1)c. C      0.021     aldehyde like                                          (1)d. A      0.1       green taste                                            (2)a. A      2.0       fruity taste                                           (2)a. C      0.016     earthy, mushroom-like                                  (2)b. A      0.25      gooseberry-like                                        (2)b. C      0.013     geranium; green; rubbery; sulfury                      TABLE VI                                                                      (1)a. B      0.6       astringert; hazel-nut, basic taste                     (1)b. B      0.25      green; earthy; hazel-nut-like                          (1)c. A      0.25      caramel-like - roasted                                                        hazelnut-like taste                                    (1)c. C      0.096     buttery; green; cereal; caramel                        (1)d. A      0.5       green; melon-like taste                                (1)e. A      0.5-1.0   fatty taste                                            (1)f. A      0.25      green, burnt, coffee-like                              (1)g. A      0.25      green, fruity, strawberry-like,                                               melon-like taste                                       (1)h. A      0.3       fatty; green                                           (1)i. A      0.6       coffee-like                                            (1)i. B      0.5       roasted, rubbery                                       (1)j. A      1.0       green                                                  (1)j. B      1.0       basic; bitter; astringent                              (1)k. A      0.3       rum-like;                                              (1)k. B      0.15      roasted; green; earthy                                 (1)l. A      1.0       green                                                  (1)l. B      0.2       green; astringent; earthy                              (1)m. A      2.0       green                                                  (1)m. B      0.6       almond-like;                                           (1)n. A      0.8       green; fatty; roasted                                  (1)n. B      0.25      basic; green; hazelnut-like                            (1)o. A      0.2       green                                                  (1)o. B      0.13      astringent, roasted; hazelnut                          (1)p. B      0.6       basic; green                                           (1)q. B      0.25      bitter; earthy; roasted                                (1)r. B      0.3       bitter; caramel                                        (1)s. B      0.75      bitter; basic                                          (1)t. B      0.45      green; astringent                                      (1)u. C      0.054     winey; buttery; acid; cereal-like;                                            sulfury; caramel; solvent-like                         TABLE VII                                                                     (1)a. A      0.3       burnt, hardnut taste                                   (1)a. B      0.4       enhanced the woody and coffee                                                 grounds note                                           (1)b. A      0.5       green, vegetable-like                                  (1)b. C      0.17      earthy, potato-like                                    (1)c. A      0.5       earthy flavor                                          (1)c. C      0.2       green; nitrobenzene                                    (1)d. A      0.5       earthy, potato-like                                    (1)d. B      0.1-0.2   enhanced the woody and coffee grounds                                         notes; adds a bitter note                              (1)d. C      0.084     earthy; green; sulfury; mouthfeel                      (1)e. A      0.25      anise-like, liquorice flavor                           (1)f. A      1.0       hazelnut, coffee-like                                  (1)g. A      0.5       anise-like                                             (1)h. A      2.0       slight caramel flavor                                  (1)i. A      0.1       earthy; potato; hazelnut taste                         (1)i. B      0.01-0.02 enhanced the coffee grounds note                       (1)i. C      0.013     earthy; green; acid                                    (1)j. B      0.06      earthy; hazelnut, burnt taste                          (1)k. B      0.45      sweet; green; burnt; astringent note                   (1)l. A      2.0       earthy note                                            (1)m. A      4.0       burnt; praline-like                                    (1)n. A      1.0       green; burnt note                                      (1)o. A      4.0       slight coffee taste; caramel; fruity                   (1)p. A      4.0       green, burnt note                                      (1)q. A      2.0       burnt; coffee-like note                                (1)r. A      0.3       fresh; hazelnut; earthy note                           (1)r. C      0.07      earthy; green note                                     (2)a. A      3.0       coffee-like taste                                      (2)b. A      0.5       burnt almond taste                                     (2)b. B      0.2-0.4   enhanced woody note                                    (2)c. A      2.0       hazelnut taste                                         (2)d. A      4.0       mild hazelnut taste                                    (2)e. A      1.0       coffee-like taste                                      (2)e. B      1.0       enhanced green and nutty notes                         (2)f. A      3.0       hazelnut, slightly burnt taste                         (2)g. A      2.5       caramel-like, fruity taste                             (2)h. A      0.5       green floral taste                                     (2)i. A      1.0       anise-like taste                                       (2)j. A      0.5       hazelnut-like taste                                    (3)a. A      1.0       burnt, roasted hazelnut-like taste                     (3)a. C      0.27      toasted                                                (3)b. A      4.0       phenolic, burnt taste                                  (3)c. A      4.0       burnt, earthy taste                                    (3)d. B      2.5       astringent; fatty; earthy                              (3)e. B      0.7       hazelnut-like; bitter; roasted                         (3)f. B      0.6       bitter; earthy                                         (3)g. B      2.5       bitter; acrid; earthy                                  (3)h. B      1.2       bitter; astringent                                     (3)i. B      2.5       bitter; acid; woody                                    (3)j. B      1.2       bitter; earthyl; woody                                 (3)k. B      1.2       bitter; earthy; fatty                                  (3)l. B      2.0       green; roasted                                         (4)a. A      2.0       roasted hazelnut-like taste                            (4)b. A      1.0       burnt, hazelnut-like taste                             (4)b. B      1.0       enhanced the green nutty note                          (4)c. A      0.5       hazelnut-like taste                                    (4)d. A      4.0       fresh hazelnut taste                                   (5)a. A      1.5       caramel- and coffee-like                               (5)b. A      1.5       anise-like, floral taste                               (5)c. A      3.0       hazelnut; slightly acid                                (5)d. A      3.0       burnt, phenolic taste                                  (5)e. A      4.0       fatty taste                                            (5)f. A      3.0       maple-like taste                                       (5)g. A      1.0       fatty taste, slightly reminiscent                                             of chocolate                                           (5)h. A      1.0       green fatty, burnt taste                               (5)i. A      5.0       fatty, hazelnut-like taste                             (5)j. A      1.0       coffee-like; green; earthy                             (6)a. A      2.0       coffee-like taste                                      (6)b. A      0.5       green taste                                            (6)c. A      1.0       hazelnut-like taste                                    (6)d. A      1.0       coffee-like taste                                      TABLE VIII                                                                    (1)a. A      5.0       fruity taste                                           (1)b. A      5.0       fruity taste                                           (1)c. A      0.5-1.0   green, fruity taste                                    (1)d. A      0.5       green, fatty taste                                     (1)e. A      0.1       fruity, fatty taste                                    (1)f. A      0.1       fatty, orange-like taste                               (1)g. A      0.1       fatty, orange-like taste                               (1)h. B      0.06      earthy, green taste                                    (1)i. B      0.06      green, fatty taste                                     (2)a. A      0.2       flowery taste                                          (2)b. B      0.9       winey, woody, green note                               (2)c. B      1.25      spicy taste                                            (2)d. A      0.5       fruity, aromatic taste                                 (2)e. A      0.5       fruity taste                                           (2)f. A      0.5       fruity taste                                           (2)g. A      4.0       sweet, slightly fatty taste                            (2)h. A      4.0       sweet, slightly fatty taste                            (2)i. A      4.0       chocolate-like taste                                   (2)j. A      4.0       chocolate-like taste                                   TABLE IX                                                                      (1)a. A      1.0       strong mustard taste                                   (1)a. B      1.0       nutty, coffee grounds-like                             (1)a. C      0.27      sulfury, ricy, phenolic taste                          (1)b. A      1.0       mustard taste                                          (1)b. C      0.08      buttery, groundsy taste                                (1)c. A      0.25-0.5  honey-like                                             (1)c. B      1.0       coffee-grounds note                                    (1)c. C      0.04      rye bread, caraway seed-like                           (1)d. A      1.0       green, water-cress like                                (1)d. C      0.68      earthy, mushroom like                                  (1)e. A      1.0       salicylate; coffee-like                                (1)e. C      0.14      mushroom-like                                          TABLE X                                                                       (1)a. A      1.0       mustard-like taste                                     (1)b. A      1.0       fruity, woody note                                     (1)c. A      1.0       woody, green, elderberry-like                          TABLE XI                                                                      (1)a. A      1.0       green taste                                            (1)b. A      1.0       fruity, woody taste                                    (1)c. A      1.0       woody, green elderberry taste                          (1)d. A      5.0       slightly woody, green taste                            TABLE XII                                                                     (1)a. A      0.3       burnt, mustard-like taste                              (1)b. A      0.1       leathery taste                                         (1)b. B      0.006     green, basic taste                                     (1)c. A      4.0       caramel-like                                           (1)d. A      1.0       roasted, hazelnut-like                                 (1)e. A      4.0       roasted, moldy flavor                                  (1)f. B      7.0       bitter, green taste                                    (1)g. B      1.9       hazelnut-coffee-like taste                             (1)h. B      6.0       bitter, burnt, coffee-like                             (1)i. A      5.0       paper-like taste                                       (1)i. B      5.0       green, roasted taste                                   (1)j. B      0.3       bitter, astringent, basic taste                        TABLE XIII                                                                    (1)a. B      15.0      sweet, slightly basic taste                            (1)b. B      0.40      astringent, bitter, roasted note                       (1)c. B      0.75      bitter, fruity, anise-like taste                       TABLE XIV                                                                     (1)a. A      1.0       tonka-bean like taste                                  (1)a. C      0.8       nutty, bitter almond taste                             (1)b. B      0.4       bitter almond, flowery note                            (1)b. C      0.08      nutty, bitter almond taste                             (1)c. B      0.25      bitter, earthy taste                                   TABLE XV                                                                      (1)a. A      1.0       benzaldehyde taste                                     (1)b. A      1.0       cherry-like taste                                      (1)b. C      0.27      bitter almond, cherry-like                             (1)c. A      1.0       saffron taste                                          (1)c. C      0.14      camphor note                                           (1)d. A      1.0       caramel taste                                          (1)e. A      1.0       burnt caramel taste                                    (2)a. B      0.06      almond, caramel, buttery taste                         (2)b. B      0.4       earthy, roasted, sweet aromatic taste                  (2)a. C      0.07      nutty, starchy taste                                   TABLE XVI                                                                     (1)a. A      2.0       burnt taste                                            (1)a. B      1.0       burnt, roasted flavor                                  (1)b. A      1.0       mint taste                                             (1)c. C      0.16      bready taste                                           (1)d. A      1.0       honey-like taste with anise note                       (1)e. A      0.5       fatty, green, caraway-like taste                       (1)f. A      1.0       slight mint taste                                      (1)g. A      3.0       earthy taste                                           (1)h. A      4.0       slightly burnt taste, slightly acid                    (1)i. B      1.2       astringent, bitter taste                               (1)i. C      1.35      cereal-like, metallic taste                            (1)j. A      3.0       earthy taste                                           (1)j. C      0.54      caramel taste                                          (1)k. A      1.0       fatty, flowery taste                                   TABLE XVII                                                                    (1)a. A      5.0       bread-like taste                                       (1)a. B      1.25      roasted note                                           (1)b. B      0.2       hazelnut, roasted, caramel note                        (1)c. A      5.0       slight hazelnut note                                   TABLE XVIII                                                                   (1)a. A      0.5       fruity, caramel-like note                              (1)b. A      0.5       fruity note                                            (1)c. A      0.2       fruity, cheesy note                                    (1)d. B      0.06      green note                                             (1)e. A      0.1       fruity, fatty note                                     (1)f. A      0.1       fatty note                                             (1)g. A      0.1       fatty note                                             (1)h. A      0.1       fruity note                                            (1)i. B      0.45      mushroom, earthy note                                  (1)j. A      2.0       fruity note                                            (1)k. A      2.0       fruity note                                            (1)l. A      2.0       acetone-like                                           (1)m. A      0.1       sweet taste                                            (1)n. B      0.45      fruity taste                                           (1)o. A      0.05      green taste                                            (1)p. B      1.5       almond-like taste                                      (1)q. B      0.125     earthy, green note                                     TABLE XIX                                                                     (1)a. A      7.0       slight caramel-like taste                              (1)b. A      4.0       slight fruity taste                                    (1)c. A      4.0       fruity taste                                           (1)d. A      4.0       fruity, cheesy note                                    (1)e. A      4.0       light burnt taste                                      (1)e. C      0.67      nutty, starchy taste                                   (1)f. A      3.0       green, hazelnut-like taste                             (1)g. A      2.0       green, burnt taste                                     (1)g. B      4.0       astringent note                                        (1)g. C      3.46      peach pit, almond taste                                (1)h. A      6.0       slight rum-like taste                                  (1)1. A      2.0       fatty, green taste                                     (1)i. C      0.54      nutty, spicy                                           (1)j. A      3.0       green taste                                            (1)k. A      5.0       weak furanic note                                      (1)k. C      0.63      fruity, banana oil flavor note                         (1)l. A      5.0       weak furanic note                                      (1)l. B      1.0       bitter, roasted note                                   (1)l. C      1.35      acid flowery note                                      (1)m. A      5.0       sweet aromatic taste                                   TABLE XX                                                                      (1)a. A      1.0       onion-like taste                                       (1)a. B      0.5-1.0   malty, roasted note                                    (1)b. A      0.25      sweet honey-like taste                                 (1)b. C      0.11      nutty, starchy taste                                   (1)d. A      1.0       burnt anthranilate-like taste                          (1)e. A      1.0       nonalactone-like taste                                 (1)f. A      1.0       wine-like taste                                        (1)g. A      1.0       sweet, flowery taste                                   (1)h. A      2.0       cream, caramel-like taste                              (1)i. A      2.0       green, mustard-like note                               (2)a. A      4.0       sweet note                                             (2)b. A      5.0       slightly roasted note                                  TABLE XXI                                                                     (1)a. A      2.0       fruity, rose-like taste                                (1)b. A      0.5       green taste                                            (1)c. A      3.0       green taste                                            (1)e. C.     0.025     geranium taste                                         (2)a. B      0.60      astringent, bitter, roasted taste                      (2)a. C      1.35      fermented taste                                        (2)b. B      0.20      astringent, peanut, roasted taste                      (3)a. B      0.60      bitter, earthy, roasted taste                          (3)b. A      1.00      grape-like taste                                       (3)b. B      0.06      fatty, bitter, roasted taste                           (3)b. C      0.06      starchy taste                                          (4)a. A      4.0       weak, sweet taste                                      (4)b. A      2.0       woody taste                                            TABLE XXII                                                                    (1)a. A      2.0       anthranilic, burnt flavor                              (1)b. A      3.0       fruity, burnt taste                                    (1)c. A      0.5       burnt nutty taste                                      (1)c. C      0.034     toasted, unroasted coffee bean note                    (1)d. A      3.0       green, grapefruit taste                                TABLE XXIII                                                                   (1)a. A      0.12      roasted, coffee-like                                   (1)a. B      0.08      hazelnut, coffee-like                                  (1)b. A      2.5       chocolate-like                                         (1)b. C      1.18      sulfury, starch-like                                   (1)c. A      5.0       burnt, roasted note                                    (1)c. B      3.0       phenolic, basic taste                                  (1)d. B      7.5       burnt, coffee-like taste                               (1)e. A      4.0       caramel, fatty taste                                   (1)e. B      5.5       bitter, green taste                                    (1)f. B      7.5       bitter, astringent note                                (1)g. A      5.0       fruity taste                                           (1)h. A      4.0       caramel, fruity taste                                  (1)i. B      2.0       bitter, musty taste                                    (1)j. B      2.5       green, woody, fruity note                              (1)k. B      45.0      astringent, bitter, musty taste                        (1)l. B      5.5       bitter, coffee-like taste                              (1)m. B      3.0       earthy taste                                           TABLE XXIV                                                                    (1)a. A      1.0       fruity, pear-like taste                                (1)a. B      0.125     green, chocolate cream-like taste                      (1)b. A      3.0       burnt buttery rum note                                 (1)c. A      3.0       strawberry-like taste                                  (1)d. A      1.0       caramel-like taste                                     (1)d. C      0.07      acid, fermented taste                                  (1)e. A      1.0       caramel-like, cocoa taste                              (1)e. C      0.34      whey, nutty taste                                      (1)f. A      2.0       fruity, butter-like taste                              (1)g. A      0.5       fruity (melon, pear-like) taste                        (1)h. B      0.1       caramel, pineapple taste                               (1)i. A      1.0       fatty, rancid note                                     (2)a. A      1.0       caramel-nutty taste                                    (2)a. C      0.41      fruity, pineapple note                                 (2)b. A      2.0       fruity taste                                           (2)c. A      2.0       fruity taste                                           (2)d. A      0.5       fruity taste                                           TABLE XXV                                                                     (1)a. A      1.0       praline-like taste                                     (1)a. B      2.0       woody, coffee grounds note                             (1)b. A      2.0       fruity taste                                           (1)c. A      1.0       egg-like taste                                         (1)c. B      0.2-0.4   woody note                                             (1)d. B      1.9       astringent, fruity, green taste                        TABLE XXVI                                                                    (1)a. B      3.0       bitter, roasted peanut taste                           (1)b. B      1.0       buttery, slightly meaty taste                          TABLE XXVII                                                                   (1)a. A      1.0       pear-like taste                                        (1)a. C      0.67      bitter, nutty taste                                    (1)b. A      2.0       gooseberry-like taste                                  (1)c. A      2.0       fruity, quince-like taste                              (1)d. A      2.0       fruity taste                                           (1)e. A      2.0       mushroom-like taste                                    (1)e. C      0.07      earthy, mushroom-like                                  (1)f. A      1.0       fruity taste                                           (1)g. A      1.0       fruity taste                                           (1)h. A      2.0       mushroom-like taste                                    (1)i. B      0.08      fruity, hydrocarbon taste                              (2)a. A      3.0       burnt taste                                            (2)a. C      0.21      buttery, vanilla-like taste                            (2)b. A      3.0       phenolic burnt note                                    (2)c. B      0.15      earthy, roasted note                                   (2)c. C      0.20      caraway seed note                                      (2)d. B      0.09      flowery, earthy note                                   (2)e. B      0.09      green, geranium note                                   (2)f. A      2.0       chocolate note                                         (2)g. B      0.65      spicy, winey, roasted almond taste                     TABLE XXVIII                                                                  (1)a. A      1.0       anthranilate-like taste with                                                  burnt note                                             (1)a. B      0.2       aromatic note                                          (1)a. C      0.135     grape note                                             (1)b. A      2.0       burnt taste                                            (1)b. C      0.135     fermented grape, sour, winey note                      (1)c. A      1.0       burnt taste                                            (1)d. A      2.0       oily, burnt taste                                      (1)d. C      0.126     apricot, astringent, acid, sour note                   (1)e. A      2.0       oily, burnt taste                                      (1)e. C      0.17      sulfury, rubbery, toasted note                         (1)f. A      2.0       earthy note                                            (2)a. A      1.0       mustard-like taste                                     (2)a. C      0.34      sweet, solvent-like                                    (2)b. A      1.0       acetate-like taste                                     TABLE XXIX                                                                    (1)a. B      4.0       astringent, bitter taste                               TABLE XXX                                                                     (1)a. A      0.25      roasted barley taste                                   (1)a. B      0.06      roasted coffee taste                                   (1)a. C      0.68      earthy, ricy taste                                     (1)b. A      0.1       burnt taste                                            (1)b. B      0.01      roasted flavor note                                    (1)b. C      0.68      groundsy, toasted, nutty note                          (1)c. A      0.5       burned, slightly rubbery note                          (1)d. A      0.05      meat broth-like                                        (1)e. A      0.1       burnt taste                                            (1)f. A      0.05      burnt, green, fatty taste                              (1)g. A      0.5-1.0   burnt, phenolic taste                                  (1)h. A      0.1       burnt taste                                            (1)h. B      0.03      bitter, roasted note                                   (1)h. C      0.05      bitter, astringent taste                               (1)i. A      0.01      burnt, meat-like taste                                 (1)i. B      0.03      bitter, astringent taste                               (1)i. C      0.01      sulfury brothy taste                                   (1)j. A      1.0       rubbery taste                                          (1)k. B      0.08      roasted taste                                          (2)a. A      1.0       styrene-like taste                                     (2)b. A      0.75      bitter roasted taste                                   (3)a. A      0.05      burnt, flowery note                                    (3)b. B      0.05      sulfurous, earthy note                                 (3)b. C      0.13      nutty, mercaptan note                                  TABLE XXXI                                                                    (1)a. A      0.03      coffee taste                                           (1)a. B      0.04      coffee taste                                           (1)a. C      0.02      sulfury, mercaptan taste                               (1)b. A      0.25      coffee-like, alliaceous note                           (1)c. A      0.25      coffee-like                                            (1)d. A      1.0       garlic-like                                            (1)e. A      0.25      coffee-like                                            (1)a. C      0.03      sulfury, sour, caramel, nutty flavor                   (1)f. A      1.0       coffee-like, mushroom                                  (1)g. A      0.1       coffee-like                                            (1)g. C      0.01      burnt, cereal, nutty taste                             (1)h. A      0.01      burnt, onion, mushroom note                            (2)a. A      0.01-0.03 mustard, onion-like                                    (2)a. B      0.004     bland coffee taste                                     (2)a. C      0.005     geranium-like                                          (2)b. A      0.05      onion-like                                             (2)c. A      0.05      onion-like                                             (2)c. B      0.02      astringent                                             (2)c. C      0.02      nutty, astringent, bitter note                         (2)d. B      0.015     fatty, earthy taste                                    (2)d. C      0.013     flowery, mercaptan taste                               (2)e. B      0.002     metallic, roasted note                                 (2)e. C      0.006     woody, bitter, nutty taste                             (2)f. A      0.001     burnt, onion, caramel note                             (3)a. A      0.2-0.5   cabbage taste                                          (3)a. C      0.067     sulfury, mercaptan-like                                (4)a. B      0.3       burnt coffee, metallic note                            (5)a. B      0.03      metallic, sulfurous note                               (5)b. B      0.06      metallic, astringent, earthy note                      TABLE XXXII                                                                   (1)a. A      0.01      coffee-like                                            (1)a. C      0.007     sulfurous, mercaptan                                   (1)b. A      0.01      garlic-like                                            (1)c. A      0.1       coffee-like                                            (1)c. B      0.01      aromatic note                                          (1)c. C      0.005     geranium, mercaptan, nutty note                        (1)d. A      0.001     burnt, coffee grounds, onion taste                     (1)e. A      0.10      burnt, onion taste                                     (2)a. A      1.0       cooked vegetable-like taste                            (2)b. A      1.0       burnt, coffee-like taste                               (2)c. A      1.0       coffee-like                                            TABLE XXXIII                                                                  (1)a. A      5.0       fortifies the bitter taste                             (1)a. C      0.093     popcorn, nutty, caramel, cereal taste                  (1)b. A      0.25      enhances the burnt note                                (1)c. A      0.25      enhances the phenolic note                             (1)d. A      5.0       enhances the burnt note                                (1)d. C      0.025     green, acid, cereal, bitter, sour                                             note                                                   (1)e. A      0.2       enhances the roast note                                (1)f. A      6.0       weak note                                              (1)g. B      0.30      roasted, astringent, earthy note                       (1)h. B      0.12      mushroom, bitter, green taste                          (1)i. B      0.25      astringent, fatty, green taste                         (1)j. B      0.40      astringent, roasted taste                              (1)k. B      0.40      astringent, green note                                 (1)l. B      0.30      bitter, green, earthy note                             (1)m. B      0.12      metallic note                                          (1)n. B      0.40      bitter fatty note                                      TABLE XXXIV                                                                   (1)a. B      0.03      metallic, burnt note                                   (1)b. B      0.01      metallic, earthy, burnt note                           (1)c. B      0.60      astringent, sulfurous, green note                      (1)d. B      0.03      metallic, sulfurous, burnt note                        TABLE XXXV                                                                    (1)a. A      0.1       roasted coffee-like taste                              (1)a. B      0.1       roasted, coffee grounds note                           (1)b. A      2.0       roasted meat-like taste                                (1)c. A      0.1       cabbage taste                                          (1)c. B      0.01-0.02 strawy, dark flavor note                               (1)d. A      0.2-0.3   cabbage, onion taste                                   (1)e. A      2.0       coffee-like taste                                      (1)e. C      0.135     sulfury, toasted, nutty, burnt                                                cereal note                                            (2)a. A      1.0       coffee-like taste                                      (2)a. C      0.135     burnt, sulfury, rubbery note                           (2)b. C      0.5       turnip-like taste                                      (2)c. A      3.0       burnt taste                                            (2)d. A      1.0       coffee-like taste                                      (2)e. A      5.0       sulfurous liver-like note                              (3)a. B      1.0       earthy, sulfurous, paper-like taste                    (3)a. C      1.08      acid, sulfurous taste                                  (3)b. B      0.12      bitter, peanut-like                                    (3)b. C      0.135     ricy, iodoform-like                                    (3)c. B      0.20      hazelnut, earthy taste                                 (3)c. C      0.22      burnt cereal-like taste                                (3)d. B      1.9       earthy-like                                            (3)d. C      2.96      burnt cereal, bitter, spicy                            (3)e. B      1.0       leathery, flowery taste                                TABLE XXXVI                                                                   (1)a. A      3.0       phenolic taste                                         (1)b. A      0.05      phenolic, burnt taste                                  (1)c. A      0.01-0.05 phenolic taste                                         (1)c. C      0.027     solvent-like                                           (1)d. A      0.01      burnt taste                                            (1)d. C      0.027     phenolic                                               (1)e. A      0.01      cresolic taste                                         (1)f. A      0.01      burnt taste                                            (1)f. B      0.02-0.04 roasted, dark flavor                                   (1)g. A      0.01      phenolic taste                                         (1)h. A      0.02      sweet, burnt taste                                     (1)h. B      0.04      coffee, coffee grounds note                            (1)i. A      0.1-0.2   slightly burnt taste                                   (1)j. A      0.15      balsam taste                                           (1)j. B      0.1       coffee grounds note                                    (1)k. A      1.5       tangerine taste                                        (1)l. A      1.0       phenolic note                                          (1)m. A      1.0       phenolic note                                          (1)n. A      6.0       phenolic note                                          (2)a. A      1.0       burnt, coffee taste                                    (2)a. B      1.0       wood flavor note                                       (2)b. A      0.01      coffee grounds note                                    (2)c. A      2.0       phenolic note                                          (2)d. A      5.0       phenolic note                                          (3)a. A      0.05-0.1  burnt taste                                            (3)a. B      0.1-0.2   smoky roasted flavor                                   (3)b. A      1.0       weak earthy note                                       (4)a. A      0.25-0.5  smoky taste                                            (4)a. B      0.4       roasted, coffee grounds note                           TABLE XXXVII                                                                  (1)a. A      5.0        slightly green taste                                  (1)b. A      3.0       burnt, caramel, slightly buttery                                              taste                                                  TABLE XXXVIII                                                                 (1)a. A      0.1-1.0   onion, garlic taste                                    (1)b. A      0.25-0.5  green, burnt coffee taste                              (1)b. B      0.4       aromatic note                                          (1)b. C      0.27      sulfury note                                           (2)a. A      5.0       slightly bland taste                                   (2)b. A      0.25      garlic, earthy taste                                   (2)b. B      0.04      roasted, natural coffee taste                          (2)b. C      0.027     bitter                                                 (2)c. B      0.025     mushroom, paper-like                                   (2)c. C      0.405     mushroom, earthy note                                  (3)a. A      1.0       burnt coffee note                                      (3)a. C      0.625     mercaptan note                                         (3)b. B      0.025     green, sweet, fatty note                               (3)b. C      0.027     earthy mushroom note                                   (3)c. A      1.0       cabbage, garlic taste                                  (4)a. A      0.1-0.2   earthy, coffee grounds note                            (4)b. A      0.5       coffee-like                                            (4)b. C      0.42      sulfury, rubbery                                       (5)a. A      1.0       caramel, coumarin-like                                 (5)a. B      0.5-1.0   aromatic, fresh note                                   (5)a. C      0.27      nutty, bitter almond taste                             ______________________________________                                    

As has been stated above the compounds having utility in the concept ofthis invention may be added to substances in varying amounts to alter orto modify the flavor of the substance by masking or blanking outundesirable flavors, by enhancing or fortifying desirable flavor orflavor notes, or by adding to the original substance an entirely new anddifferent flavor. As will also be apparent to those skilled in the artvarious mixtures or blends of the flavor agents described may be used toachieve a desired flavor or flavor note. If, for example, one wishes toenhance a certain flavor note, or group of flavor notes present in asubstance such as coffee, one needs only mix together certain of thedescribed flavor agents to obtain the desired result.

Following are three examples of mixtures that have been prepared inaccordance with the inventive concept.

                                      TABLE XXXIX                                 __________________________________________________________________________    Compound                  Parts by weight                                     Identification                                                                         Name             Ex. 1                                                                              Ex. 2 Ex. 3                                    __________________________________________________________________________    VII (1) a                                                                              2-methyl-3-ethyl-pyrazine                                                                      --   40    20                                       VII (1) i                                                                              2,3-diethyl-pyrazine                                                                           --   --    0.5                                      VII (1) d                                                                              2-methyl-3-isopropyl-pyrazine                                                                  5    5     7.5                                      XVII (1) b                                                                             2-acetyl-pyrazine                                                                              --   30    10                                                2-methyl-3-methylthio-pyrazine                                                                 2    --    2                                        XXXI (1) a                                                                             furfurylthiol acetate                                                                          2    2     3                                                 furfuryl methyl sulfide                                                                        --   1     --                                       XX (1) a 2-acetyl thiophene                                                                             --80 --                                             XXXI (2) b                                                                             furfuryl propyl sulfide                                                                        --   3     1                                        XXXVIII (2) b                                                                          2,6-dimethyl-γ-thiopyrone                                                                4    4     4                                        XXX (1) a                                                                              2-methoxybenzenethiol                                                                          --   12    6                                                 2-hydroxyphenyl methyl sulfide                                                                 1    2     1.5                                      XXXVI (1) i                                                                            3,4-xylenol      4    4     2                                        XXXVI (1) k                                                                            2-hydroxyacetophenone                                                                          --   --    5                                        XXXVI (3) a                                                                            4-ethyl-2-methoxy-phenol                                                                       --   5     2.5                                      XXXVI (1) c                                                                            4-ethyl-phenol   --   --    0.5                                               pyridine         20   30    20                                       III (2) e                                                                              2-vinyl-benzofuran                                                                             3    3     4                                        XXXVI (4) a                                                                            4-vinyl-1,2-dimethoxy-benzene                                                                  --   40    --                                       XXVI (1) a                                                                             furfuryl propionate                                                                            --   50    --                                                furfural         --   100   --                                       __________________________________________________________________________

When added to a commercially available soluble powdered coffee beveragethese blends of flavor agents added flavor notes which enhanced theflavor of the soluble coffee in the direction of that of roasted andground coffee which has been brewed into a coffee beverage.

In order to demonstrate the flavor modifying or enhancing effect of thecompounds of this invention a base material having the followingcomposition was prepared:

    Compound            Parts by weight                                           ______________________________________                                        3-methyl-cyclopentane-1,2-dione                                                                   50                                                        furfuryl alcohol    50                                                        furfural            10                                                        diacetyl            5                                                         acetylmethylcarbinol                                                                              30                                                        benzyl alcohol      100                                                       propylene glycol    755                                                                           1000                                                      ______________________________________                                    

Compounds of Group XXXV (Pyrazine Sulfur Compounds) were added to thisbase in varying amounts and the resulting compound mixtures were used toenhance or modify the flavor of the following food products:

a. A solution of milk sweetened with sugar, at a dosage level of 10grams of the flavor composition per 100 kg.

b. A prepared ice-cream, at a dosage level of 10-15 g. of flavorcomposition per 100 kg.

c. A white cake mix, at a level of 20 g. per 100 kg. of finished cake

d. A milk pudding, at a dosage level of 10-15 g. per 100 kg.

e. A milk chocolate, at a dosage level of 25 g. per 100 kg.

The exact formulation of the various compound mixtures are set out inthe TABLE XL below.

                                      TABLE XL                                    __________________________________________________________________________    Compound            Parts by weight                                           Identification Name Examples                                                  __________________________________________________________________________                        4   5   6   7   8   9                                     XXXV (2) a                                                                           2-pyrazinyl-ethyl-                                                                         100 --  --  --  50  50                                           mercaptan                                                              XXXV (2) b                                                                           2-pyrazinyl-ethyl methyl                                                                   --  30  --  --  --  5                                            sulfide                                                                XXXV (2) c                                                                           2-pyrazinyl-ethyl ethyl                                                                    --  --  125 --  --  20                                           sulfide                                                                XXXV (2) d                                                                           2-pyrazinyl-ethyl                                                                          --  --  --  100 50  35                                           furfuryl sulfide                                                              3-methyl-cyclopentane-                                                                     50  50  50  50  50  50                                           1,2-dione                                                                     furfuryl alcohol                                                                           50  50  50  50  50  50                                           furfural     10  10  10  10  10  10                                           diacetyl     5   5   5   5   5   5                                            acetylmethyl carbinol                                                                      30  30  30  30  30  30                                           benzyl alcohol                                                                             100 100 100 100 100 100                                          propylene glycol                                                                           655 725 630 655 655 655                                                       1000                                                                              1000                                                                              1000                                                                              1000                                                                              1000                                                                              1000                                  __________________________________________________________________________

All of the compounds of Examples b 4-9 gave a resulting flavormodification in the food products which was organolepticallycharacterized as adding a definite roasted coffee flavor note.

A number of the Compounds of Group VII (Pyrazine Hydrocarbons) wereadded to the above described base material. The resulting compoundmixtures had the formulations shown in TABLE XLI below.

                                      TABLE XLI                                   __________________________________________________________________________    Compound            Parts by weight                                           Identification Name Examples                                                  __________________________________________________________________________                        10  11  12  13  14  15  16  17                            VII (1) h                                                                            2,3-dimethyl-pyrazine                                                                      250 --  --  --  --  --  50  --                            VII (1) a                                                                            2-methyl-3-ethyl-                                                                          --  25  --  --  --  20  15  10                                   pyrazine                                                               VII (1) c                                                                            2-methyl-3-propyl-                                                                         --  --  45  --  --  25  --  15                                   pyrazine                                                               VII (1) d                                                                            2-methyl-3-isopro-                                                                         --  --  --  45  --  --  --  20                                   pyl-pyrazine                                                           VII (1) i                                                                            2-ethyl-3-ethyl-                                                                           --  --  --  --  10  --  5   2                                    pyrazine (10% soln.)                                                          3-methyl-cyclopentane-                                                                     50  50  50  50  50  50  50  50                                   1,2-dione                                                                     furfuryl alcohol                                                                           50  50  50  50  50  50  50  50                                   furfural     10  10  10  10  10  10  10  10                                   diacetyl     5   5   5   5   5   5   5   5                                    acetylmethylcarbinol                                                                       30  30  30  30  30  30  30  30                                   benzyl alcohol                                                                             100 100 100 100 100 100 100 100                                  propylene glycol                                                                           505 730 710 710 745 710 685 708                                               1000                                                                              1000                                                                              1000                                                                              1000                                                                              1000                                                                              1000                                                                              1000                                                                              1000                          __________________________________________________________________________

When added to the same food products at the same dosage levels asdescribed in connection with the Examples of TABLE XL above, thecompound mixtures of Examples 10-17 imparted a pronounced nutty, green,fresh, earthy flavor note, with a light note of coffee grounds, to thefoods.

Further compound mixtures utilizing mixtures of compounds from GroupXXXV (Pyrazine Sulfur Compounds) and from Group VII (PyrazineHydrocarbons) were made as set out in TABLE XLII below.

                                      TABLE XLII                                  __________________________________________________________________________    Compound              Parts by weight                                         Identification Name   Examples                                                __________________________________________________________________________                          18  19  20  21                                          XXXV (2) a                                                                           2-pyrazinyl-ethylmercaptan                                                                   20  20  20  20                                          XXXV (2) d                                                                           2-pyrazinyl-ethyl furfuryl                                                                   20  20  20  20                                                 sulfide                                                                 VII (1) a                                                                           2-methyl-3-ethyl-pyrazine                                                                    --  --  10  10                                           VII (1) c                                                                           2-methyl-3-propyl-pyrazine                                                                   --  --  20  5                                            VII (1) i                                                                           2,3-diethyl-pyrazine                                                                         --  10  --  5                                                  (10% solution)                                                                3-methyl-cyclopentane-                                                                       50  50  50  50                                                 1,2-dione                                                                     furfuryl alcohol                                                                             50  50  50  50                                                 furfural       10  10  10  10                                                 diacetyl       5   5   5   5                                                  acetylmethylcarbinol                                                                         30  30  30  30                                                 benzyl alcohol 100 100 100 100                                                propylene glycol                                                                             715 705 685 695                                                               1000                                                                              1000                                                                              1000                                                                              1000                                        __________________________________________________________________________

When added to the same food products as above and in the same dosagelevels, the foods were found to have their flavor modified to one with adefinite coffee flavor with a light touch of a coffee grounds note.

Some further compound mixtures were prepared from compounds of Group VII(Pyrazine Hydrocarbons) using as a base the following mixture:

                          Parts by weight                                         3-methyl-cyclopentane-1,2-dione                                                                        200                                                  Essence of cinnamon      10                                                   Essence of sweet fennel  20                                                   Essence of star anise    20                                                   benzyl alcohol           250                                                  propylene glycol         500                                                                          1000                                              

The exact formulations of these compound mixtures are set out in TABLEXLIII below.

                                      TABLE XLIII                                 __________________________________________________________________________    Compound               Parts by weight                                        Identification Name    Examples                                               __________________________________________________________________________                           22  23  24  25  26                                     VII (1) e                                                                            2-methyl-3-butyl-pyrazine                                                                     25  --  --  --  5                                      VII (1) b                                                                            2-methyl-3-isobutyl-pyrazine                                                                  --  50  --  --  15                                     VII (1) f                                                                            2-methyl-3-amyl-pyrazine                                                                      --  --  100 --  20                                     VII (1) g                                                                            2-methyl-3-hexyl-pyrazine                                                                     --  --  --  50  15                                            3-methyl-cyclopentane-1,2-                                                                    2000                                                                              200 200 200 200                                           dione                                                                         Essence of cinnamon                                                                           10  10  10  10  10                                            Essence of sweet fennel                                                                       20  20  20  20  20                                            Essence of star anise                                                                         20  20  20  20  20                                            benzyl alcohol  250 250 250 250 250                                           propylene glycol                                                                              475 450 400 450 445                                                           1000                                                                              1000                                                                              1000                                                                              1000                                                                              1000                                   __________________________________________________________________________

When added to a soft gum-drop candy formulation at a dosage level of 30g. per 100 kg., to an ice-cream mix at a dosage level of 8-10 g. per 100kg., to milk pudding mix at a dosage level of 8-10 g. per 100 kg., andto a hard candy formulation at a dosage level of 15-20 g. per 100 kg.,the compound mixtures imparted a definite anise, liquorice-like flavornote to the finished products.

It should be kept in mind, as will be appreciated by thoseskilled-in-the-art, that with many flavors it is possible to imitate thenatural flavor by selecting a limited number of the flavor enhancingsubstances examplified above. Coffee aroma, on the other hand, is muchmore complex than the ordinary flavoring materials and may necessitatethe combination of many more of the examplified ingredients forreproduction.

It will also be understood that whereas the preferred embodiment of thisinvention is directed toward the enhancement or modification of coffeeflavors, the concept of the invention has much wider application. Whilesome of the compounds may be characterized by terms which are notdirectly related to coffee flavors, these comounds, when used in morecomplex formulae, may contribute desirable flavor notes to the overallflavor and aroma.

To summarize briefly this invention relates to a group of chemicalcompounds which have been found to have utility for the alteration ormodification of the flavor of other materials. These compounds, calledflavor agents or flavor modifiers, may be used in minute quantities toenhance the natural flavor of substances to which they are added, or toalter or modify a flavor which is undesirable, or to impart to asubstance additional or different flavors or flavor notes. The flavoragents of the invention are used in minor, but flavor altering amounts,in any case, in quantities sufficient to obtain the desired results. Theflavor modifiers are of particular importance and usefulness in themodification, alteration or enhancement of the flavor of coffeebeverages made from soluble coffee and the preferred embodiment of theinvention contemplates their use in conjunction with such products.

The flavor agents of the invention may be added at a convenient step inthe soluble coffee process such as plating the dried soluble coffee witha desired dilution of the flavor agent in an acceptable solutionfollowed by drying. In certain instances the desired agent may be addeddirectly to a concentrated coffee extract and the mixture dried into asoluble coffee product which contains the flavor agent as an integralpart thereof. Other methods of incorporation of the agents will suggestthemselves to those skilled in the art and may, of course, be usedwithout departing from the inventive concept, which may be described asbeing a composition of matter comprising a combination of a solublecoffee product, however prepared, whether liquid or solid, concentratedor dilute, which contains combined therewith a minor, but flavormodifying amount, of a flavor agent as described herein.

What is claimed:
 1. The chemical compound 5-methyl-furfuryl furfuryl ether. 